I was wondering if I was the only one who uses the battery profiles. When I switched from the DroidX the Thunderbolt, this was one feature I missed immensely. Now that Im back on the Bionic, Im loving it. It saves immense battery by turning off the data connection when the screen is off. When sitting idle with the data connection off, the phone using about 1% per hour. Ive noticed with the data connection on, it uses 3-4% per hour when idle.
I have my phone turn off data after 30 mins. Turning the screen on re-establishes the connection and resets the data timeout.
The main downside to this, is you wont get push notifications when the radio switches off. I understand many people rely on push notifications, but if you're someone like me who doesnt need to get gmail, fb, twitter, etc right when it happens, then this is a great method for saving a huge amount of battery. Calls and texts still come through right away when the data connection is off.
Also, since Google Voice uses data, I set it up to send me texts when I have a new VM or text message instead of getting those notifications through the app.