Last week my XPS M1330 was repaired (after I dropped it!).
I've been using a Macbook Pro 15 inch for that last few months while I procrastinated about calling Dell to get the XPS repaired. I also need the MBP for
Unity and other graphical work.
I have to say, going back the XPS (with Ubuntu) is like a breath of fresh air. It's nicer to type on, has page up page down keys, a brighter screen. Using Ubuntu also feels much cleaner. I can't explain "cleaner", but it just feels that way compared to OS X. I know I can run Ubuntu on the MBP, but I thought I should give OSX a fair go. I'm pretty sure that I'll start using Ubuntu again for web and server code development, and leave the MBP for Unity and other graphical work.
It's really hard to get used to two different laptop keyboards though. :-)