If you're comparing an 8130 on Verizon to an 8100 on T-mobile, you will notice a speed difference when using web based apps. The 8130 offers EVDO support, T-Mobile uses EDGE. EVDO offers higher connection speeds, the 8130s on Verizon and Sprint both support EVDO. To me that is the biggest difference between the 8100 and the 8130, the camera's nice, the side loading sd is nice, but EVDO is the clincher. (provided your area supports it, some areas don't have EVDO reception on either carrier. However if you live in a major metro, odds are you will.) I use the web and download alot, so the faster the connection, the happier I am.