Played both Zealot and Psycher to the highest levels and difficulties. Experimenting with multiple skill and feat combinations and multiple staff combinations.
Psycher is definitely the weakest, and that’s with good gear. Its also gets weaker the higher the difficulty level. It reaches its limits in Heresy. I can be check mated on Psycher way more often than on Zealot.
Zealot for me to be Checkmated will usually take Gunners + Bulworks/Ragers/Maulers + Horde + Special. Usually 3 of those groups at once.
Psycher it only takes two of those groups. I can last with Surge, but that only lasts until overcharge max is reached. But switching between staff and BB to handle that kind of thing in my face usually means I’ll take a couple of hits. and Overcharge is reached WAY too quickly without the corresponding power to even take many down with me.
It is blatantly obvious when playing the two which one is weaker and needs some work. No you can’t out Purgatus a Flamer. Voidstrike you can come close to the Plasma gun but only by Spaming repeatedly, but the real problem with Psycher is you can’t really handle specials that well without Surge Staff. Brain Burst is simply not strong enough in the highest difficulties and and takes far too long to use, and needs multiple applications.
You have too much switching and fiddling to accomplish the same things that other classes do with less effort and at the same power level. It would be different if it were stronger when you do all that fiddling, but it’s not. Its most often weaker despite all that.