I gave up trying to fix the GPS and was happy that my WIFI worked so well. When I bought my prime GPS was still listed as a feature, I've been really lucky to have this tablet since the beginning of 2012, and have enjoyed it immensely. I realized a BT GPS solution was possible after working with some iPad's set up for ocean navigation. I decided one day to stream the GPS from a phone over BT to the transformer prime, and I couldn't be happier with the results.
Here's the step by step to setup GPS BT Streaming to a TF201 (although it is applicable to many tablets including an iPad with suitable changes to the instructions).
1) root the PHONE (not the Tablet)
2) download "Bluetooth GPS" on the prime (or tablet) by googoo android. This will receive the GPS signal over bluetooth.
3) enable mock locations under developer settings on the prime settings
4) download a GPS to Bluetooth app on the PHONE. There are several
4.1) I use "Bluetooth gps" by meowsbox free trial 1.49 full version
4.2) you will need to grant su privileges to the GPS to Bluetooth app you use
4.3) some apps work better with certain phones
5) start GPS and gps streaming utilizing utility from #4 on the phone
6) pair phone and prime under bluetooth settings, in the settings menu of both tech.
7) open up Bluetooth GPS on the prime choose the PHONE from the dropdown source menu and click connect
8) you should now be able to utilize GPS as if it were native on the prime
8.1) you can see feed from bluetooth gps, see sats with GPS test, utilize maps or special nav charts e.g. boats planes etc.
Let me know if I skipped a step or can make this clearer.