im in the puget sound which was one of the first places to get the refarmed network. im using a lumia 900 at&t. i unlocked it for tmobile after i did the update yesterday. i do get "4g" but its sporadic. im not sure if its due to the update or what since i wasnt able to test it before i installed 7.8 but the symptoms are oddly familiar to what was plaguing this phone back in april.... on the lock screen itll show 4g, as soon as i jump into the browser and try to search something, it jumps down to edge. lock the screen again, wait about 15 seconds or so and 4g pops right back up. go into the brower once more and same result..edge..... this is with strong signal strength and in areas where my unlocked one x locks on 4g and phones before it like a 4s and s3.