Lets clear this up once and for all.
Mac is a lifestyle computer. It's got all the essential software to assist you in your daily matters. From reminders, calendars to pics, videos, sound and backup solutions. I LOVE the universal zoom function... I know, naughty, naughty....
These are stuff that comes FREE with every single Mac.
Audio MIDI setup for easy detection, assignment of your Recording gear.
Gigabit MIDI over network for composing with sampler Macs.
Distributed DSP plugin processing over Gigabit network when working with Logic Studio
(This means you could just buy Macs to process tons and tons of plugins over Gigabit Ethernet! Goodbye TDM)
Aggregate Audio device editor to combine/reclock several Audio interfaces to behave and respond as a unit.
Time machine for daily/ weekly/ monthly backup
Time machine or Disk utility system restore if your HDisk crashes.
iChat for Secure video conferencing between chambers and booths, collaborations and recording.
Screen-sharing for connecting to your Mac from anywhere in the world.
itunes for organizing your music.
GarageBand for practicing/ recording/ creating your demos.
Address book to store all your contacts/ Fan data base.
Safari for web browsing, myspacing and facebooking.
iCal for planning and publishing your gigs with details, pics and subscription.
Mail for email blasting to your database.
iPhoto for editing your gig photos. (publish to flikr, facebook option)
iMovie for editing your gig videos. (publish to youtube option)
iDVD for creating DVD Presskits.
iWeb for creating and updating your webpages.
ichat conferencing to keep in touch with family while touring.
More at apple.com
All "i" Applications (eg. iWeb/ iDVD) work with each other what Apple refers to as "Round-Tripping".
This means all your pictures, music and video files could be previewed and accessed, say in GarageBand to create a podcast or a song.
Or dragged from the media area in iDVD to create DVD audio/video
Or using your GarageBand creations in your iPhoto slideshow.
If you decide to go pro, there are solutions that will suit each and every level of your creative needs... At a very decent price as well!!!
You can't go wrong with a Mac. If all else fails, run Windows on your Mac.. As far as I can understand, Macs will dominate for a little while longer than expected.
All you need now is a pair of ATHM50, a pair of Rokit 5s, An Audio interface from Line6 (comes with decent guitar emulators), your SM57/58, you and your instrument.
What are you waiting for?
Hope this helped.