The mental combat was kinda not mathed.
The archive.wizards article that lets Psion 3
go ahead and dump 5 of those for feats
is quite tasty.
Things were different back then, with way
fewer posters scratching for every detail.
Tiers is probably the most significant since,
so with 3.0e psi, Tier 5 is standard homegame,
Tier 4 is I've read a guide, Tier 3 is working
quite hard to make the combos line up.
CoDzilla was known about (if not yet coined)
and old psi couldn't really get there much.
Bruce Cordell (the lead author) had a bunch
of side projects that were/are compatible.
If Thoughts Could Kill and Hyperconscious.
Still a few posters around here, have 3.0 street cred.
Robby Pants perhaps, some of the gamingden guys.