I also had the swollen battery problem but my 9550 - my trackpad eventually got pushed up 1/4 of an inch or so. The bummer was that my laptop was out of warranty and the battery is not a "user serviceable option" on the 9550 so I couldn't just order a replacement battery from Dell -- they wanted me to send it in and wait two weeks which was a non-starter as it is my main development machine. I ended up buying a used battery off of some guy on Amazon along with a screwdriver kit with a T5 bit. It took me all of 10 minutes to replace the battery.

I haven't had any other problems but the fact that they won't allow end-users to replace such a simple part as the battery will make me think hard when I replace this laptop.