trav, thanks for the link. The launch angle issue seems to be one where personal preference plays a big part in what would be desirable for any particular player. In my case, I greatly prefer launch angle differences even though I am often subject to issues caused by the spin of the incoming ball. I play against a couple of people who can hit really heavy underspin and it is hard for me to effectively volley against them, especially on the forehand side, because I don't always get the angle correct to compensate for the amount of spin I believe the shot has. I seem to put these into the tape more than anything, and then the next time I overcompensate and float the volley long. Both guys, both righties, seem to put more underspin when going down the line than crosscourt and that compounds the issue against my less reliable forehand volley.
The flip side, though, is that high launch angles seem self-compensating with my strokes. If I swing at a groundstroke and it happens to bounce higher than I am expecting, I usually won't time it perfectly and so there's less ballspeed off my racquet, but a higher launch angle means that my more upward stroke at it gets more air under the shot, and it has greater depth that way. Conversely, if the ball bounces a little lower or faster than I am expecting, I'll tend to catch it with a slightly closed face and a high launch angle can help the ball just skim over the net instead of hitting it.
Same with an extremely extended backhand slice, one where I am almost 180 degrees turned around to get maximum reach. In that position, it's impossible for me to do anything but hit an underspin and lead with the bottom of the racquet face, and having the strings grab the ball makes it a less floaty, deeper shot. A grippy stringbed, sensitive to incoming spin, also has helped me with drop volleys. It was almost a relevation the first time I tried a shaped poly and found that hitting a drop volley off a heavy underspin shot was so much easier than with the round poly that I was using before that.
In any case, it's not launch angle why I lose to the same guys in age group matches. I play an unsustainable style for someone in my late 50's because I'm still trying to play like a modern young player. That's effective to a certain level, but the top guys in the 55's all train juniors so all of a sudden my game is something they see all the time, and they win me out by putting balls in difficult spots and waiting until I miss. Or waiting until we get to 3-3 and then I get broken because I try to do something special in my next service game and make an extra error that loses me my serve.
Interesting to note that none of the top age groupers in the 55's hit with anything more than moderate pace and moderate spin. There's a lesson there for me, only I'm too stubborn to take it and believe in it.