great inputs and analysis. Thanks for the write up. I always enjoy the scientific and theory side of things.
Yes, I am currently still playing with kevlar. Though kevlar according to this
losses tons of tension 20+ lbs after a bit of hitting. I've been using it since I was a kid with about a 7 year break from not playing. I actually don't like it per se but returning serves with new/tight strings is a lot easier for me. I actually take 1st and 2nd serves on the rise and come in to the net. Once the tension goes taking serves on the rise is very tough and the ball just catapults.
Kevlar with MSV hex has given me no arm troubles. But Kevlar with Forten Sweet at 70lbs feels like a board and my arm is starting to feel it. I'm going to dial it down.
Thanks again to the both of you for the knowledgeable input.