I want to be fair about my response to this question: The three Elevate Tours that we have are string with Solstice Black 18 at 53 lbs (our reference string and tension), Elite XT 18 @ 53 lbs, and Solstice Power 18 @ 51 lbs respectively. They were strung by the Diadem folks and they did a great job of it, and the frames took a little less than a week getting to Seattle from Florida, probably in pretty cold conditions the whole way. My kid has been a Solstice Black 18 die hard for awhile now, but I wanted him to try some comparable Diadem strings just to see what he thought of them. When we stumbled upon Solstice Black it was by pure accident, so there wasn't much evaluation or variety in that choice. He just liked it, and it was very obviously good for his game. All that being said, he still likes the Black in the new frame, but (surprisingly to me since he tends to be very loyal to things he likes) he likes the Elite XT a bit better cuz it is a bit stiffer but still retains the playability of the Black. I believe the logic to stringing the Power at 51 vs 53 was that I had read and heard that Power was deader than Black so I wanted to give it a fair shot by going a couple of pounds looser. He likes this as well, it just isn't quite as responsive as the Elite or the Black in his opinion. There is a wild card string floating around in our stringing room, which is Pro X, which we haven't tried just yet, not sure what he will think of it as it is not shaped like the three strings currently in the frames (he is not a big spin player but recognizes that having easy access to spin is helpful) but by eveything I've heard should play similar to the Elite XT but with maybe a bit more pop. I will report in on that whenever that happens. The kid strings his own, so he chooses what to strng with. I can offer fatherly guidance, but its his tennis, not mine.