There were three major changes to psionics over previous XCOM games. The first and most obvious change is the need to have the target within vision range. This part is okay and was probably a much needed nerf. Even in OpenXCOM, using LoS psionics alters the weapon from a map sweeping God Mode into a risky but potentially powerful weapon. The second change is the addition of PSI energy. It is used with every single PSI ability and as an additional upkeep cost to maintain attacks. The differences between turn based and real time are fairly major here as a successful attack in turn based will burn maximum energy to full effect(1 energy per TU), even if you didn't need it all. Real time psionics require time to take full effect (draining energy) and can be shut off any time. The third change is much more subtle but just as important. Half the aliens in Apocalypse don't have brains! Even when you want to use Psionics, there are so many targets that are simply immune or have insanely good PSI defense. So what went wrong in Apoc? In my experience PSI energy is the biggest problem. You simply don't get enough! Energy is consumed insanely fast (it regens at a paltry 1:sec or 11:turn) and agents can burn out from merely attempting an ability. IMO psionic energy needs to be doubled (or consumption halved), and agents on BOTH sides need more recovery speed. Perhaps an XCOM item could help recover PSI energy? My best attempt with Psionics was cheating agents to have 255 energy and insane attack/defense. The energy was enough for a really good mind control and could have stunned 2 or 3 guys. Still, it couldn't compare with a 96 accuracy Toxigun super soldier in the slightest. PSI morphs have what... 150'ish energy? Even then they burn out pretty quick. The huge number of PSI immune aliens is a huge bummer and doesn't really make sense at all. I mean I can understand that simple aliens don't have enough brain for an XCOM agent to mind control it and force it to make coherent choices. But don't forget. Everything in this game is based on a Psionic entity! The Micronoid aggregate conquers its victims through a combination of psionic compulsion and by being a parasite. A hybrid soldier would KNOW this after dealing with enough aliens to understand their quirks, and with some training or gear alteration they should be able to attack the entity directly (just like the Toxigun does). So things like psionic stun could still be available and have decent odds, even if the target isn't something that can be controlled. It may have even explained the purpose of the Psionic Blast ability, which was never implemented in game.