You'll probably want pretty high system specs for Classic WB. Or at least match your specs to the package you download.
IMHO "Classic WB" is too un-Amiga-like for my taste, but obviously that's just my opinion. 
I like ClassicWB Lite, which is what I use on my MiST (pretty much a real A1200+030, specs wise). It's very light on Chip and Fast RAM, very fast, and looks like my real A1200 Workbench did in the mid 90's. It uses regular WB rather than Scalos, so it acts and behaves more like how I remember Workbench.
