Zerk is fine, stop crying because it`s not as op as in KF1.
I totally disliked zerk in KF1 because it was so op and boring and I was very suprised and happy as I tryed this new Zerk and noticed how well balanced it is now.
The only true Thing you complaining Guys said about Zerk is, that Tier 2 and Tier 4 should get a LITTLE buff.
Also I wouldn`t complain about changed Skills even though I`m fine with them as they are.
But giving him more Strenght, Resistance, HP or Speed would just result in a terrible op Perk just as it was in KF1.
As it is now, Zerk is not the
"I`m going solo till my Team is dead and finish the Rest on my own, Perk."
And thats a good Thing.
Zerk needs his Team, especially Medics now, just as every other Perk needs different Perks to compensate the own certain Weakness.
Thats how you get a good co-op Game.
Btw, just yesterday I played a Game on suicidal with zerk 25 using only the shovel+ medicgun and my Team had another Zerk, a Commando, 2 Medics and a Support and we did very well.
Stop complaining about it but learn how to play it!