Interesting to see how long the S3 has endured as a development device.
I had an S2 back in the day, which was similarly easy to root and flash custom roms onto, but the GPS was notoriously unreliable on any custom ROM. The standard advice at the time, if you were having a trouble getting a GPS lock, was literally to flash the stock ROM back onto the phone, get a lock, and then flash your custom ROM.
I got to the point where I was doing it several times a week, and then said screw it, I don't have time for this.
I wonder if that problem was ever resolved in later phones.