I'm very seriously considering the i7 over a Mac Pro at the moment, and it would be exclusively for running Logic. I've been really encouraged by the couple of posts from people using it for Logic and having good results! Please can I ask for more information?
At the moment I'm trying to run sessions on my MBP, which isn't working out so well. The MBP is my "everything" machine, so it's cluttered with other software to the gills. Its 2.4GHz Core 2 Duo gets flustered pretty quickly with the sessions I'm throwing at it. These are usually pretty light on audio tracks but heavy on virtual instrument tracks – I'm using the Rhodes and Hammond emulations a lot, plus Kontakt, plus occasional EXS24, plus other 3rd-party stuff... plus of course nice modelled EQs and other processors. The MBP starts to stutter at the point where my track is about 70% done, and even freezing and altering buffers only buys me so much grunt.
I've been saving for a "music only" machine for a year now, and waiting for the new Mac Pros avidly. But the news on that front seems pretty mixed (take a look at their forums – they're not happy bunnies over there). The bottom line seems to be bad price/performance ratio in the lower-end machines, which is all I can afford in any case. So the top-end iMac suddenly starts to look very tempting.
Please, anyone who's using Logic, could you give me an idea of what kinds of
sessions the i7 is able to handle? What kind of virtual instruments (and in what quantities) you're throwing at it? EG, I'd love to know what AlienSporeBomb's "most intense logic session" looked like. Then maybe I can get a good idea of what to expect. I would dearly, dearly love to be able to make music without constantly having to micro-manage the computer to hold things together...
Finally, also on the musical front, how intrusive are you finding any hard drive noise? Quiet is important: it's going to be sitting 3 feet from the microphone, more or less. And finally finally, any thoughts on how worth-it the SSD option is – and what would you use it for? System drive, or sample storage for Kontakt / EXS24?
Many thanks (for reading all this, if nothing else...

)!