Psionics is different in each edition. 1e psionic feats, 2e non-caster "Psionicist", 3e full-caster "Psion", 4e psionic "power source".
The "Psion" is a specific class that needs to be a full-caster, and I am grateful the majority of the feedback seems to agree. Apparently, at least 60% of the feedback is satisfied with the Psion with slot-9 spells, like the 3e Psion had. The Psionic community had been notoriously devoid of any consensus. To be able to pass the 60% threshold is an enormous accomplishment − that might have been unthinkable a few years ago.
I respect the process. Fortunately, the psionics that are most important to me, seems to be gaining consensus. Psionic flavor is now "normal" in the core rules, there will be a proper Psion class, and it will use normal mechanics, the same way all other classes do.
Psionics is vital medieval flavor. It is the power of "thought", and the power of an individuals "soul". There are many premodern examples of this across many cultures, including European cultures. This flavor needs to be normal in D&D.
The recent update made telepathy and telekinesis impressive − they needed to be! − and I am satisfied.
The 5e Psion class is "design by democracy". Happily the major decisions happened to go my way. But some of the minor stuff didnt.
I am less a fan of "nosebleed" psionics, but heh, apparently too many people do like it. At least the flavor emphasizes that this magic source is (1) personal thought and (2) draws from the lifeforce of the soul. The Psion has too few hit points to be wasting precious hit dice on spells. But the flavor is there, and there will probably be dramatic moments when it does happen.
The use of external "gp costs" for spell components is profoundly nonpsionic flavor. It is painful to see Psion have to faff around with them. Even so, the gp component is something I have been complaining about since 2014, even before 5e even had player psionic options. (I understood the problem and saw it coming.) I wish there was a better way to prevent spamming certain spells. I am ok with the way the 5e Psion uses the Somatic component. At least this is ones own body.
I love full-caster spells. I prefer the Psion uses spell points to fuel them instead of spell slots. Then again, I prefer all spellcasters use spell points − Wizard, Bard, Druid, ... and Psion − especially to simplify the caster classes at the highest levels. Perhaps the same book that publishes the Psion, can also provide an optional spell point system that any class can use. Preferably the spell point system refreshes per Short Rest instead of Long Rest. It would be the same way that the indy Laserllama does it.
Regarding power sources, I suggest Arcane and Divine utilize the "weave" but Psionic and Primal dont. Rather, Psionic and Primal utilize the soul. The power sources might be like D&D alignments, where the narrative is very important, but actual mechanics is a nuisance.
I feel Charisma makes more sense for the Psion class than Intelligence does. Mind powers have less to do with math, and more to do with poetry. The only way I can reconcile Intelligence, is to emphasize that the Intelligence ability is every kind of knowledge, including intuitive "psychic" knowledge. In other words, a DM can as for an Intelligence (Investigation) skill check, in order to do a tarot-card reading that accurately predicts the future or acquires detailed information remotely. If Intelligence is intuitive, then I am ok with the Psion keying Intelligence.
All in all, I either love or can live with everything about the updated Psion class. In other words, it is perfect.
The 3e full-caster Psion now has a satisfying 5e incarnation. But we still dont see a 2e "Psionicist" incarnation. Maybe if one squints one might explain the various 5e classes that have psionic subclasses as splitting up the the 2e non-caster mechanics. If there is to be a proper 5e Psionicist noncaster class, then I think this Psionicist, the "simple" caster class (analogous to the Fighter Champion), and a "superhero" class are all the same thing. Consider Superman. He only has a handful of powers: airy flight, earthy strength, watery cold breath, fiery laser beam eyes, and perhaps ethereal x-ray vision. Not alot spells, yet he is one of the most powerful superheroes in existence. Almost every superpower can be explained by psionics, whether telekinetic flight or psychometabolic shapeshifting. A simple Psionicist class with X-men in mind, simple to play, avoids spellcasting mechanics, and flavorwise fits right in within a medieval setting.
