I've found my golden egg when it comes to this racket, what i use is:
Yonex poly tour pro 125 Mains.
Babolat pro hurricane 120 crosses.
I'm not really a stringbreaker, and it lasts about 4-6 hours before i cut them out, but it might go somewhere around 8-10 before it snaps(depends on the quallity of my hittingpartners).
The hard babolat crosses cut into the softer mains, so the snapback still happens even after 2-3 hours.
I must say that the spin is incredible, ive stunned numerous players with both my crosscourt forehand, where i sometimes put an higher arch and some sidespin on, it just explodes off court.
Same goes for my onehanded backhand, it just amazing how much spin it adds.