That's because on computer that slow you never actually experienced "speed" . On my 8 core Mac Pro with 32 GB of RAM Lion is noticeably slower than Snow Leopard.
Stupid animations for opening new app windows are total waste of time. Too many usability regressions and paradigm shifts (breakages) are just too much. I wish they would break OS X into two, technology fearing ignorati get OS X home and UNIX geeks get OS X Pro, but it will never happen.
It's really time to re-think my computing needs. Obviously using Apple computers for all my needs is no longer viable.