well, on one of my 2000's it has a Magnum 040 and I put in about 48 megs or something. like you - when I got my spectrum card i also had an orgasmic experience, so to speak, but it happened again when i installed OS3.9 (on that system I had 3.1 before)
that really made a big difference. there was no change in hardware but everything moved faster. and i use the newest Cybergfx - no problems at all.
2000's have limitations but they are good workers and i like mine alot.