Yesterday I strung up a Fischer vacuum SC mid (predecessor to the vacuum 90 pro) with Prince Tournament Nylon @ 32/30. Some guy next to me broke his strings so I lend him my racket. He seemed to be playing great but the mass was too much for him.
Afterwards I asked him: would you believe me if I told you this was strung at 30 lbs? He just looked at me in shock. He could not believe it. He went over to his friend and asked: Guess what this is tensioned at? The guy replied no idea but we usually string at 55lbs. Well guess what, it's strung at 30! Both guys are players who've been playing for years. The looked like they've never heard such a thing in all their years of playing tennis.
The guys just could not believe it felt so nice! He asked what makes it great. My guess was the ball sinks more into the stringbed impacting more spin.
I really liked it, but my technique isn't solid enough the constantly play with a narrow mid. When I hit off center my elbow gets a beating. I'm really contemplating stringing up my regular racket with a premium multi @ ELT. I don't have the same string so I could't compare.