If someone was producing PCs with the build quality of Apple hardware, I would struggle to think of many compelling reasons not to switch and run linux. Maybe this is it.
I've had my MBP for three years. In that time, I had to replace the topcase (keyboard/touchpad) conveniently after one year warranty expired. I found a replacement on Ebay, however I lost most of my function keys and two-finger touch on touchpad. My battery is toast and doesn't last five minutes without adapter. I've had to replace my adapter. My screen died about 2.5 years in, this was covered by warranty. Also the bezel around the screen has cracked on both sides, so screen is supported by the back shell and wobbles slightly.
The OS is far better than alternatives though so I suffer with it all.
If i didn't have the three year warranty i could have thrown mine away:
1. the NVIDIA chip died > screen goes black: known issuse: http://support.apple.com/kb/TS2377
basically if you have one of those macbooks, it will most likely die sooner or later, if it dies within the first three years you're lucky.
2. the trackpad stops working > known issue: the topcase needs to be replaced.
3. cd drive stopped working... well.
bad quality basically. but i would probably buy one again, because there are no slim pc-notebooks.