Any reason why you dumped T-Mobile?
I dumped AT&T due to two problems, in rural areas their network more often than not failed to properly do handoff's, causing my handset to lose a signal requiring a hard reset to change sites, it was worse with data rather than voice.
The other was pricing, even with my employee concession I could get a lower monthly price with T-Mobile than I could with AT&T, when I did the first port out I was sent off to retention's and they couldn't match T-Mobiles pricing at the time.
Now I think they have adjusted their rates downward somewhat, but I am still not going back.
Plus they are still having hand off problems I have seen it happen when monitoring the network.
The third reason was monitoring, I know of two former co-workers who got into jams due to where they where surfing using their own devices, not company devices, I found that to be quite telling.