So far in the polls, it seems about 84% of AD&D 1e players used Psionics at some point.
I selected "used in every 1E campaign". However, to clarify, I gave everyone a chance to use psionics. I believe the rules were that you ha to roll a 20 on a d20 in order to have psionic abilities. (High INT PCs may have been able to roll a 19 or 20)
During the entire 1E era, only one player in my campaign successfully rolled a 20 for psionics.
Much of my bitd gameplay was BX/BECMI (with AD&D add-ons as we saw fit). For both that and AD&D, psionics was much like weapon vs armor, name level keep & commander play, or the comeliness attribute: the first time we were exposed to it, we got really excited about it. Then actual play happened and it ranged from relatively trivial to a pain in the butt to deal with (often with only the DM and one player really participating). And then it faded into the background until someone new entered the group, found the rules, and got really excited about them.
- In the other older ones, including OD&D, 2e, 3/3.5e did you use them?
It was an interesting departure and more power to them for making those choices. I don't love the idea of making monk abilities and psionics the same source, but that's personal preference.
- Did you like having them front and center in 4e?
I don't think it would be horrible if there wasn't more mechanical support than 3-4 sub-classes. Totally new rulesets alongside existing magic hasn't had the greatest track record (otoh the playtest mystic was not a bad first try, the could have become something if they had kept going). That said, either way I think there should have been an expansion (or a chapter within a XGtE/TCoE-like book) calling those abilities psionics (optionally) and discussing the ins and outs of including psionics (thematically) in your campaign.
- Does 5e have enough, too much, or not even close?

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.