Reflashing to another version is a placebo. GPS is unreliable no matter what. It might work perfectly for a couple of weeks and lead you to think you've found a solution. It will be broken again soon. No software revision, no Samsung repair, and no Sprint repair will do the trick. I've tried them all. Try running a GPS tracking app and hiking into a hill. It will permanently lose lock as soon as you lose your cell signal.
Here's how I fixed mine. Worked perfectly. I sold the Epic Touch and got the S III ... Problem solved. It's like when you stop hitting your finger with a hammer.
You bought another Samsung? I don't think I'll give them another penny for a decade. I'm looking forward to the end of my Sprint contract too.
The SIII is a great computer, has a quick-locking GPS, and runs Android 4.1.2 (and higher ifyou want to bother). It doesn't drop calls, and the battery life is fine for me . The only difficulty in my case is that it is a 4G LTE modem, and there is no 4G LTE in my area, and no prospects either (Washington DC). Apparently Sprint thinks it is a higher priority to bring 4G LTE to Longview and kerrville Texas and Shelby North Carolina (no offense intended, small towns) where they have 35 customers, and not to large cities where they have tens of thousands. They are giving them away for free when you renew. At least from what I read, the S IV isn't really that much better. The Epic 4g Touch almost made me leave Sprint, too. They pushed that phone hard, knowing it was buggy and basically a useless brick. Their behavior was indefensible, unethical, and moronic. Now I'm glad I sold it and moved on. Your mileage may vary. Good luck.