Larger Laptop HD

I need to get a larger laptop hard drive, but I’m torn between getting a drive with smaller size, 120GB, but faster at 7200 RPM. Or I get a larger drive, 250GB, but slower at 5400 RPM. The kicker is the 250GB drive is cheaper as well… Hm… So many choices. Do I sacrifice speed for price and size? Or do I only go for the speed?

For some reason I’m leaning towards the faster drive, smaller size for a little more money. I don’t think I want to accept a slower machine and it would be noticeably slower.