I also charged it on my Amex, but I am keeping the $200 warranty. From what I read in the internet, there is alot to do to get your laptop repair under Amex double warranty coverage and the whole process can be short (like Bestbuy warranty) or can be very long... plus you might have to pay shipping yourself. Battery and dead pixels not cover at all through Amex.
Now I am thinking $130 for new battery (if you run on battery alot, the battery will lose it's life after a year or so), the extra convience of just droping off at any Bestbuy, easier and faster warranty repair and no calling around or paper faxing or mailing through Amex, a bit more coverage against wear and tear, and easier to sell this 2 years from now with the warranty still attached, then the $200 make alot of sense to me anyway.