To add further fodder to software choice discussion on this
site: both major Mac-only DAWs have won Key Buy awards from Keyboard Magazine, Apple's Logic Pro and MOTU Digital Performer. DP won its Key Buy
in my review of version 4.5, which came out in the February
Keyboard; for excerpts see MOTU's site. Francis Preve gave Logic Pro 7 a glowing review earlier.

(updated with links)
Logic Pro 7 Review (Francis Preve)
MOTU Digital Performer 4.5 Review (Peter Kirn)

If you haven't made up your mind
yet, check out the reviews in KB and other publications and see which
is best for you. I'm just glad to see this market having matured to the
point where so many tools (Logic, DP, Cubase, SONAR, Tracktion, Live,
and of course Pro Tools) are strong choices. Even if sometimes I get
teary about the days when I started out on Cakewalk 4 for DOS.