Ok here's an experiment I just did to test 4G issues.
History: My bionic lost 4G connection late last night, and has spotty 3G connection. voice calls work fine. Phone is a personal phone, purchased on 9/8 in Centra CA.
My Samsung 4G mifi has a solid 4G connection sitting next to my bionic. Device was purchased early this year on a corporate account in Central Texas.
Experiment: swap sim cards!
So I took the sim card from the mifi and installed it in my bionic, booted up, bam, within seconds, strong 4G connection. ran a bunch of speed tests, and loaded up a bunch of web sites, updated about a dozen apps. no problems for the 10 minutes I let it run.
Next, took the SIM that came with my bionic and installed it in the samsung mifi, powered it up, no 3g or 4g, searching constantly, over a 10 minute period it was able to get onto 3g for a short periods of time (20 seconds or so) a few times, but couldn't maintain connection.
Next put the SIM that came with the samsung back in it. Instant 4G connection.
Put the SIM that came with my bionic back in the bionic, no data signal, voice works fine.
So it sounds like there are some really strange 4G issues (seems to be tied to particular sim card(s)?
Just thought it was interesting enough to share.
BTW in the few minutes it took me to type this, my bionic has gone from no data to 1x to 3g and back to no data about a dozen times.
the samsung mifi still shows strong 4G connection.