Comments for speed
But a Thinkpad, then use one of those hacks to put OS X on it.
I can't image not having linux around for my desktop, I also own a mac but I don't know , there are alot of things that irritate me, for example I can't seem to find a decent rss agrregator for MacOSX (I don't want to pay) alot of applications cost money.
Now I'm running Gentoo next to MacOSX and I'm quite happy with it.
Did you read the anandtech article about the OS X kernel being slower than linux. They did make a point there and I'm beginning to notice it too. I'm a new convert to OS X and everything rocks but for decent developement work I think the OS is a tad bit slow !!