Hmm don't have those problems with mine yet and the computer is 3 years old. I am a little concerned about the potential for the 8600M GT problem that might arise with this computer, but as I understand it, it will be covered by apple care. Other than that, this computer is great to use for being just $350.
Mine's almost 5 years old now, and I've had all of those problems, just not to a severe degree. Temps are starting to get a bit out of hand-- running at 79 right now even with a notebook cooler-- but it's HOT in this apartment (temporary living arrangement) so I won't complain. I plan to keep this notebook for another 3-4 years, if it lasts.
I would love the 17"! I have always wanted a 17 and even got a Santa Rosa one for a bit, but sold it for a cool $700. Someone wanted it even more.
My biggest regret has been not going for the 17". Two of my friends have them and they're amazing machines. But one of those friends is moving to a 12" Tablet PC (partially for school, partially because of the size/weight) so I guess it gets old after awhile