Thing with portables and me, is that I put these machiens through hell. Goes back and forth to work a few times a week, thrown around in the pack in the truck, exposure to heat/cold... way more abuse than a desktop would ever get put through... then there's the part density. Pack the power of a computer into a little 1" thick piece of plastic, and yeah, something's bound to go wrong.
Most of the logic board replacements were take-it-in, swap-it-out and i'm good to go half an hour later. All at no cost to me.
Had my 2nd iBook for 2 years before the LB crapped out on it. Took it in, swapped out the LB and ordered some other parts that were worn out. Parts came in but they weren't for my rev iBook, so rather than saying "Sorry, hope what you have on there works", they gave me a new computer.
Had this MB for over two years now, replaced kbd/trackpad/top case a few months ago, recently having some issues with bluetooth, but again, it's all still under warranty. It breaks, they fix it.
As I mentioned above, I am NOT very gentle with these machines. I'll take all the problems with my Macs in teh past 10 years than having to deal with the crap windows throws at me at home as well as at work. Nice to come home from a day of beating hell out of my work laptop out of frustration to a computer that just plain works and doesn't crash.