I have always owned extended batteries from Seidio Extended Battery except this time for my Droid.
One of the reasons I switched from my Storm1, and 2 was because of size, it was so NICE and sleek.
The additional bulk that the battery and door have make this little phone look and feel bad in my opinion.
There is a extra amount of juice that the battery offers but it looks awkward to me when adding the battery/door..
I am looking forward to reviewing the Slim extended battery that they (hopefully) will be offering shortly.