Thanks D!
I thought gut also lost it's tension after a few weeks.
Thanks for the info.
Must be time for me to look into USRSA membership/certification......again. 
Everything looses tension over time and use. But there is no synthetic string that comes close to gut when it comes to, well, anything. Playabilty, power, and significantly tension loss.
Think of it this way. What is gut? It's usually made from sheep or cow intestine fiber (the greener the grass the better the gut
). Intestines are designed by nature, or God, or whomever, to expand and contract over and over over the life of whatever beast it is in. Food comes in, it expands, food gets digested it contracts to it's orignal form. That's what the fiber is designed for and no synthetic fiber comes close to it when it comes to expanding and contracting to its original form.
Well, that sure makes sense!!! Is there a particular gut you prefer and what is the average play time per string job?
I haven't enough experience to have a preference, I talk to a master stringer and let him decide, I wanted to try ALU rough to get more spin, but he told me the strings won't effect the amount of spin, it's all in the technique, and save my money. Right now I get tremendous spin by changing my technique, I only have to work on moving my body as one unit. Like a great bagua zhang grandmaster told me, when one thing moves everything moves.
I play 1 or 2 times a week, each one is 2.5 to 3.5 hours. I've had the current strings in there for 3 months and haven't noticed any change in the racquet so I'm happy, maybe next year I'll try another combination with my own input. The racquet may be changing but so is my game and technique so it's hard to tell.
What on earth is a "great bagua zhang grandmaster"? 
It's called circle walking, kind of hard to describe. google "bagua zhang".
ie.
The practice of circle walking, or 'Turning the Circle', as it is sometimes called, is baguazhang's characteristic method of stance and movement training. Practitioners walk around the edge of a circle in various stances, facing the center, and periodically change direction as they execute forms.
