This is a phrase that should cause some trepidation for android phone users (no idea about the iPhone). After the last update this phone started running slow, then the crashes began.
Researches turned up little help other than the only likely fix was either rooting (not great with 1 year of warranty left) or resetting so it loses everything. In the end I just had enough, backed up through Sandisk memoryzone and told it to forget everything.
It didn't disappoint.
I had at least hoped restoring from a backup would recover all my text messages, though I can't complain really since everything else apart from basic layout has been fully recovered. Contrary to my expectation, saving apps to the SD card did not stop them being erased, though the system (presumably Google) did remember I'd bought endomondo pro so it didn't have to be bought again.
So it's been just like any other computer rebuild. Once the OS is working you restore data, reinstall apps and tweak things around to improve the previous set up and try new stuff. I'be used the phone for several hours now, and apart from a bizarre glitch at the start it seems stable and mostly OK.
I hope it continues, because it's a darn nuisance to do all this again.