I`ve just bought a Go720 to replace my broken 910.
Wiped the internal memory, installed 9.510, ran clearflash, patched the maps / speedcams and it works perfectly
The only issue I`ve found so far is every time I power it up, I still get the annoying Legal Notice screen and have to click `I agree`. I also had this issue on 9.485. I gather it`s something TomTom implemented, probably some disclaimer they had to introduce, but still annoying.
Still testing, but it has been fine for the last few days.