Okay Scott...
My two cents. The Prince Pro Blend was great string, Kevlar and Prince Syngut soft, very good combo. (By the way my experience with Stamina was the same, not very good for durability. I get strings sent to me all the time and have tried most of them.
But...my problem with Kevlar was just the stiffness and it did start to give me arm problems. I went for a time with the same string in very thin Kevlar, they used to call it thin blend and was made by Ashaway. This gave great "bite" on the ball but you lost some durability with the thinner gauge. But if the arm and shoulders hold up, hey this may be a combo for you!
Kevlar with tear through the stamina but if the are still good you can just remove the Stamina and restring crosses. I have done this for myself. I have never done it for anyone else.
Polyester is also a way to go for durabilty, but you lose such feel. Not a big fan of so called durable strings. But I string so durability isn't an issue. I can always drag more frames to the court. I may have ten racquets of the frames I use now so keeping some strung isn't a problem.
Right now I have two strung with gut and one with Prince XX Lightning and one with Babolat syngut. There are days when gut doesn't work or I may save the gut for a real match. I may only be one more hit away from snapping the one gut and the other hasn't been hit with.
I talk too much. Have a nice day.
Paul S
Hey Scott... nearly 80 here today! How is your weather.