I just bought a second hand macbook because my netbook was slowing down, and also because it seemed a good idea to have a portable studio computer... and it's BRILLIANT!
You can't see it here but this is me looking at it.
I've been slightly out of sorts because I made myself a strange schedule - I suddenly felt I should work more, and I did not realise my plan added up to nine hour days working on three books. This made me feel kind of rather unwell. I promised myself to remember that four hours of creative work a day are THE LIMIT. And sometimes two are ok, especially if there is a mountain of admin to be dealt with.
Freelance work is great, but more stressful than you'd think - being paid in extremely uneven chunks of money long after you finished your work so that sometimes you're paid while you do nothing and sometimes you're poor while working double shifts. Keeping track of what you need to do and when without working yourself into the ground or freaking out about maybe being lazy... it's hard.
I wouldn't want it any other way, though.