My favorite racquet has Gosen Polymaster II strung at 48# in the mains, hybrided with Prince synthetic gut at 62# in the crosses. I've used it for 8 months now and like it a lot. My doubles partners across the net don't like that racquet but the one on my side likes it fine
It gives my serves a ton of kick, especially the second serve. My groundies tend to dip in with these strings. Volleys are crisp. I've tried regular poly's, and other spin polys, but I prefer this one. I have shoulder/wrist issues with regular polys, wanted something a little softer with spin and this works great for me.
The recommended tension for this string is 45-55#. It's better than Gosen's Comfort Poly and priced accordingly. This is the poly I tend to recommend to friends.