Just thought I'd add a little more to this thread...
In regards to spin, I'm not really sure if ELT gives more or not, but I do have a couple of observations that occurred after stringing at 30. First, I have noticed a slightly higher trajectory over the net. I've read that studies show only a 1 or 2% increase, but this is translating into 1-2 feet higher on average. To go along with this, I've mysteriously developed a very high trajectory (maybe 8-10 ft over the net) ball since going to ELT. The interesting thing is it usually only happens when I'm pressed a bit. It lands about 3 ft from the baseline and then shoots up over my opponent's head. Really useful in forcing errors or neutralizing attacks.
The next thing I noticed is that I now have a solid drop shot. I hate drop shots because they are so darn effective, and I couldn't pull it off very well. Now I seem to throw in several every couple of games. I figured that I might see more topspin, but this intrigues me because not only is it backspin, but also requires a light touch. Based on the traditional thought of the tramopline effect, I thought that type of shot might be impossible, yet here they are, showing up in my game.
Again, I'm not sure what the science behind tension says, but these two shots have crept into my game over the last few weeks. Maybe I'm stroking better, maybe switching to leather is helping--I really don't know. Bottom line, though, I'm doing things that I wasn't before, and it's fun--especially watching guys try to catch the high looper on the backhand side.
PK 7G w/BHBR 17g X Weiss Cannon Silverstring 17g @ 30lbs