I have a couple questions but first a little background. I'm a 3.5 player who just concluded a fairly successful season at 4.0. I play 4-5 hours a week but plan to play more often this fall. I have a 2-handed backhand and hit relatively flat off both wings. I play an all-court singles game and alot of doubles with my Head Microgel Extreme(16x19 100si). I never thought much about strings until I came across this forum. I've only tried two strings so far at mid tension (a.) Synthetic gut (Head Syn. Gut PPS 17) ) and (b.) Multi (Wilson NXT 17). I've noticed that after 7-8 hours my strings start to feel mushy. My shots feel decent (good depth and pace) until my strings go mushy then my shots (serve, fh, bh) start sailing long. I also find the string movement of the NXT to be extremely annoying. Q1: Which strings would you recommend? Higher tension? Q2: Does it make sense to use different strings for doubles versus singles?