yeah I use an apple powerbook G4
You pay a little extra for apple products. If you have to liase with work and they use windows operating systems it can be a little difficult. If your just using it for photo, music, web, video and office its fine.
Windows documents open on Mac office no probs. Check out
www.computerwarehouse.co.uk
The top end Powerbook is now around £1500 £1600 and as of yet there are no G5 powerbook being released. When you see the clock speed of mac you can more or less add 1/3rd or even double it to get the speed advetised by pc's.
You pay a little more for the design and ease of use. Also Ive only ever had 3-4 virus's on my machine as theres only a handful written for the mac nothing to 70,000 written for PC's.
Also worth checkin out is an apple base station which will wireless your web connection and music, wireless mouse and keyboard. If you buy a G5 Desktop then just by a LCD monitor. I can recommed the CTX 19inch from dabs.com for £225.00 probably cheaper now.
Once you go mac you wont ever go back.