Personally i have owned to very high end laptops a NP9262 and the one i am currently using a NP8120. I have never had any issues with any of my hardware if anything they have ran much better then i had expected, since i am a avid gamer i have always tried to find the best products and research everything pretty good before i made purchases. Call it luck or whatever i have never had a bad nvidia product.
But currently in the mobile gpu market i would have to say go for ati. More bang for your buck and not the same refreshed chipset over and over again. Although the new 480M's are coming or are out the the cost the performance ratio is well in favor of the ati cards. Maybe nvidia will gets is act together but for the time being i would get a ati 5870 if at all possible. Probably the best all around card on the market for mobile gamers if you are looking for a good cost to performance ratio.