I'm giving JLB7.0 another go and this time I did manage to fix the GPS using the steps from this
thread and installing
LBESec twice (restarting each time), then replacing the
NetworkLocation.apk in the system/app folder (and changing to the correct permissions as the previous file had) using ES File Explorer (or Root Explorer), however, now incoming calls are not working.
I can make phone calls and send/receive texts, but I can't receive phone calls. Very strange. I was hoping to test out battery life, but obviously with this deficiency, I will have to go back to MIUI Android 3.1.25 once again.