I've heard many people point to poly strings being the chief culprit in the demise of serve and volley tennis (including Agassi). I really don't understand this. I'm not much into equipments, but aren't poly strings just synthetic fibre strings that have been around for decades? Has there been some kind of revolution in synthetic fibre technology while I was in sleep? I've started playing tennis in the early '80s, and I've always used synthetic strings because of their durability and affordability. But I always longed to play with natural gut, and loved that feel when somebody lent me one. Almost all the pros then used natural gut strings. No one thought otherwise. Most of the years, I've played with Prostaff Orig. Mid (St. Vincent) and tried various synthetic strings (really cheapo to more high priced). No one string gave me particularly bigger power. It was all about the feel - whether I liked it or not - and the quality of my shots (not the power). Then, with my coach's recommendation, since a few years ago, I've made the switch to 95 sq. in. racquet with Luxilon Alu-Power string. One tough and long-lasting string, I thought. And the new racquet gave me plenty of power. But I didn't like the feel of the deadness the string gave me, and I've switched to Wilson NXT (supposedly similar to natural gut) which I liked for volleying and continued to use for 3 years now. To me Alu-power and NXT do not have power differences. But to me different racquets gave me different powers. I'm a 4.0 guy (very close to going up a notch in my estimation). All these talks of Luxilon uber alles sound like hype to me. Are my techniques not modern enough to fully appreciate the increased power potential of modern strings?