You need the .27 radio on t-mobile.
For those that don't have those issues, good for you. no need to post. This is to help those that are having problems.
The only drawback is that you have to downgrade everything. IT IS IMPORTANT TO USE ONLY THE 4.2.1 android. The .27 radio will not work with 4.2.2 and you will not be able to make/receive calls as well as many other things broken.
UPDATE: You can use the latest 4.2.2 cyanogen (CM10) with the latest m1 franco kernel with the .27 radio. Other 4.2.2. roms have not been tested and may or may not work. It has been reported hit or miss on it working with other roms.
1. Download the 4.2.1 any rom (cyanogen peferred) to phone storage. Here is the link to the older cyanogen nighties. I recommend the 01/25 build.
2. Download franco kernel r72 for the 4.2.1 series to phone storage.
You must use this kernel as it has the Qualcom drop out fix.
3. Download the .27 radio to phone storage, you need this radio for the reception and drop outs.
4. Flash all that stuff above in the recovery. Flash the radio first then reboot into recovery, then flash the ROM, then flash the kernel.
If you want faster HSPA speeds switch your t-mobile APN from epc.tmobile.com to lte.tmobile.com (thats LTE in lower letters.)
However, if you do that you will have to switch the apn back to simple if you go out of the hspa area or you may not get data on E or G.
If you don't get any data after editing that, just hit the 3 verticle dots on the upper right, under the APN menu, and hit reset to default apn settings. The reboot phone.
<-------HIT MY THANKS BUTTON
This will make you go from liking you nexus to loving it.
Also switching from Pre-paid to Post paid enables roaming. There is no roaming on pre paid. Since there are no contracts, there is nothing to lose.