EXS 24 Logic Sampler Users Group

hello everybody,
i'm actually using an icebook500, emi2|6 and logic 4.8.1, exs.. etc

I desperately need automation right now so i should upgrade to logic 5.
Problem is i've been told logic5 is much more cpu demanding, and with my
icebook500 and 4.8.1 i'm alredy on the edge (just 1 platinumverb and some
compressors before running out of cpu).
So i guess if i upgrade to logic5 i'll have automation but NO cpu for a
single reverb!\ufffd? (anyone has tried this setup?)

Therefore i'm thinking about going with the mbox and ptoolsLE for recording
and mixing (as the icebook500 runs PTools LE fine with automation and
several reverbs, comps, eqs..) and use logic just for midi
composing/notation.
So, does the digi mbox really work with logic -with propagama or whatever
driver- under low latency settings? low latency enough to play live exs24
from a midi KB?

thanx in advance,
jindrich.