I work with an Imac 27 "with a sound card and 3GB RME Fireface 400 and I have not encountered any problems until now
J ' Logic Pro since version 7 and I mean I can not get enough.
What I like most is the management of plugs is very clean. Each parameter can be found very easily. Nothing to do with cubase.
The internal plugs are good but should be supplemented by others. Sounds already prepared are very good too.
A good sequencer for me ...