It is a commonly held position that the Assault class is overpowered in PVP and way underpowered in PVE. While that is a form of balance, I suppose, I am going to focus on issues and possible solutions for the PVE player. 

Strengths: 

Assault has 1 great perk: Non-lethal gunstrikes restore armor. 

it has 3 good perks: the level 8 signature perk +50% damage for 10 sec, and the +100% damage -50% area, 10% recharge per kill

It has 1 okay team perk: +30% gunstrike damage 

Weaknesses:

First and foremost, it is unanimously agreed upon in the community, Assault should have 3 charges to its jump pack. 

Issues: The jump pack dodge build/perks. I mean, with all the respect, its just bad. Its not intuitive to use. Having two buttons do the same thing, dodge. And its a waste of a charge unless you use the level 25 perk, which is just intentionally nerfing your character. The only signature perk for assault that is any good is the top of the column, +50% damage for 10 seconds...and thats new since update 6.0. The jump pack dodge build maximizes mobility, but thats all it does. It might synergize well with the new perk tree for the heavy assault pistol, where you now get a +20% range damage boost for every use of the class ability, but by comparison to every other class, it is still woefully underwhelming. Every other class has at least one good perk in every column, that just isnt true for Assault. 

Assault really should have 3 charges. 

Which leads to the second issue. Perks for assault in general. It is the only class that has perks where you have to accept tradeoffs for ability. No other class has something like +20% damage, but adds 25% to prep time to ground pound. The "perk" by percentage, is less powerful than the time youre adding to gain its benefit...placing assault characters where they are most vulnerable, in the air. In other words, the values should be swapped, it should be +25% to damage, but takes 20% longer. Having the red number be larger than the green number doesnt make it feel like a good perk. And to a lesser extent, the +100% ground pound damage but -50% to area. This is standard to use, but given everything else, it just adds to the level of underwhelming for the class. The area reduction should only be 25%, not 50%.  There is no way to maximize the cooldown perk with the reduced area perk, you have to have an absolute horde to get the coveted 3rd consecutive ground pound. 

And it shouldnt be coveted, it should be standard, because again, Assault really should have 3 charges. 

Assault team perks. The gunstrike at 50% was great, hands down the best option...being to nerfed to 30% makes it just okay. But the other two options are still bad. +10% ability recharge rate. Then look at vanguard....team perk is +15% ability recharge per majoris execution. Sniper is +10% recharge per headshot kill. And then Assaults worst team perk, +20% damage to Extremis and Terminus...meanwhile tactical offers +15% ranged damage. Vanguard offers +15% melee damage, global. There just arent enough extremis and terminus enemies to justify using the team perk that only comes into effect against them. This is why some snobbish players will boot Assault players, because they dont think the class is any good to use, but more than that, it offers nothing to the team perk either. A bad vanguard player is still valuable to keep around just for the +15% ability recharge on executions. Assault should offer a flat +20% ability recharge rate. And the team perk, instead of extremis, should be +25% to block/parry window for the team. Thats not overpowered, it would be unique to the class since no other class offers it, and it would actually be viable and useful. 

Moreover, Assault and Bulwark neither benefit from the Heavy +20% ammo team perk. Because that perk doesnt apply to secondaries, and those classes only have secondaries. So now you have 2 of 3 team perks being just not useful for the team. If its about avoiding a meta and having people picking a variety of loadouts, I never see Heavies pick anything other than the ammo perk. 

Heavy bolt pistol should not be available for every class. IT should be limited to assault, bulwark and heavy. Heres why. Because vanguard and tactical are already the most over powered classes. Tactical already has the heavy bolt rifle for the heavy headshot modifier, all the ranged damage bonus modifiers possible, and prestige perks for ranged damage. It does enough damage without the heavy bolt pistol. Emperors vengeance doesnt refill secondary ammo. So youre going to have players start taking ammo crates that otherwise wouldnt, to refill their new heavy pistols. This will make the ammo needy classes, sniper/heavy/bulwark/assault suffer...all so the two classes that are the most powerful, the most lethal, with the best perks, to have a new toy. I have already seen it happen in the PTS. Tactical has the plasma pistol now, cool. It also has +15% ranged damage team perk, +40% damage to plasma weapons (at 30% overheat), +25% secondary damage until reload (which is great with plasma pistol...now its just a constant 25% damage boost) and +20% ranged damage prestige perk...that by itself is +100% damage without any kind of clock or countdown or adding in the auspex scan buffs. Tactical shouldnt have the heavy bolt pistol. Vanguard and Sniper dont have the same argument, but each have their own ways of being absolutely OP by comparison. 

Also, the heavy bolt pistol basically has a nerfed version of the best Assault signature perk. Using the class ability, +20% damage for 10 seconds. No other class has their signature perk being vultured like that. And I suspect its anti-synergy with Assault now. Do you get the +20% from the gun and the +50% from the assault perk? Because I have used both assault and tactical with heavy bolt pistol in PTS, and tactical just outshines assault with it, what was once its signature gun and the only reason I chose to play assault to begin with. I wanted to use the heavy bolt pistol, got good with assault because of it. To now see the same gun in other classes and being better than it is for Assault is just...kind of a slap in the face. Very demoralizing, seriously. 

finally, the +10% cooldown per enemy killed perk, while good...creates a situation where Assault players have to play selfishly if they want to actually get any use out of their second best perk. So every time there is a large gathering, the assault player will Dash ahead and ground pound the large group. EVERY TIME. I have had players say, "hey I want to kill bad guys too"...to me. I often have players leave after a single game. And I know its because I do that, kill every large group by myself. It makes it to where they only get into heavy combat whenver there is a wave. And its another reason why players will kick assault players...because it scans as being selfish. I get it, I feel it too when I play as other classes. And again, its the only class that has something like this...that incentives the players to do stuff that is kind of anti social in order to get the best performance out of the class. 

HOW TO FIX IT: 

Assault should have 3 charges. 

Assault absolutely NEEDS a "+25% damage while jet pack is cooling down" perk. That can replace the perfect dodge perk in the top row of columns, because again, jet pack dodge is bad and needs to be entirely overhauled. 

Team perk: replace Extremis/Terminus damage with block/parry window, revert gunstrike to 50% or failing that, bump it to 40%. Its already the least powerful, most suffering class, dont take away its only definitely good team perk. 

It needs the executing majoris +15% ability recharge as a class perk, not a team perk like vanguard. That will solve the slow recharge rate, and mitigate the anti social, destroy all large groups...and it will synergize well with the reduced area, higher damage perk, because it will make immediate executions rewarding for both armor and ability recharge. 

There needs to be a heavy bolt pistol specific perk, the same way Sniper has a Las Fusil perk. Something like +50% damage for heavy bolt pistol when you are under 50% ammo. Something like that wouldnt be overpowered, it would make the ammo economy better for Assault, it would incentize the player to skip ammo crates/share with other players, and it would make him more lethal as he gets closer to empty of ammo. Added bonus, Assault players are often in trouble against terminus enemies becuase they run out of ammo, especially Neurothrope. This would solve that, make them more lethal against terminus, and boost survivability as a passive effect. 

The +15% melee damage to majoris/extremis, should just be +15% melee damage. It doesnt make any sense to have to hit gaunts three times with the hammer. 

Instead of the jump pack dodge, focus perks on recouping health/ammo. NOT ARMOR. The gunstrike has armor solved. 

This got really long and I hope you read it all. But the biggest takeaway remains...ASSAULT really should have 3 charges of the jumppack. Almost everything else would be solved with just that change. All by itself. And its already that way in PVP. Assault in PVE needs 3 charges, please...for the love of the God Emperor, please.