Probably renders slow b/c of a slow harddrive setup. I would try getting a second HDD to do RAID0 and then seeing how that goes.

I'm currently messing with Premiere on an Alienware & it's incredibly slow... even for just playing videos that are out on the harddrive... plays through the buffer and then starts dropping frames left and right. New computer, will have the harddrives set up in RAID1+0, that I'm building should be much better.

Personally, I would never get a Mac. Too expensive... you can build a PC for half the price... but price is not a big deal, then you might want to look into it... just make sure it has a RAID0 setup.