A quick tap of the Xbox button in the top center of the controller allows, to use PC lingo, «Alt - tabbing» away from the crashed game, so you can close it gracefully and restart it. (gamingtrend.com)
It's a very light controller and handles well, although the R button did not work on the unit I tried and the Z button was near the top center of the controller between the L and R buttons. (pressthebuttons.com)
Recently, a Chinese forum posted some exclusive pics of the PlayStation phone, sporting an Xperia logo on the center of the controller. (fonearena.com)