I hadn't realized how abusive a relationship I had been in with the Blackberry Storm(other than I know it was slow and buggy) until I switched to a Droid X last fall. The screen is better, the interface is better, it has a good GPS with good software to go with said GPS. I love it. The problem is that, if I am hiking for hours and hours on it, or over a weekend, or at a amusement park, etc. the battery is in real danger of it running out...especially since I use the phone a lot more than with the Storm!
So I got a "expanded battery".
The new battery has 1880 mAh worth of capacity, versus the default 1500 mAh. Since the battery is every so slightly bigger, a different battery cover is needed.
But honestly it looks just the same as my other one, and my protective case fits on it just as well before. So far it seems to be functioning fine.