OK, something strange: I was recalibrating my extended battery. With the back off, I also changed SD cards. The connection time was so bad I couldn't even access these forums. Finished charging the battery, change everything back - good data connection again. Not sure scientifically, since speed test app isn't working, but there is DEFINITELY a difference! Tomorrow I will try SD and battery separately. But, how could either of those two make any difference?
Sent from my stock Thunderbolt