FWIW. Here's my limited experience with the 99s.
As a little background, I'm a USTA computer ranked 4.5. I play an all around game, with speed, consistency and forehand my strengths. I mostly use a one-hand backhand, both slice and topspin. I sometimes return with 2 hands. I've been a long time 12oz+ racket user, mainly the Wilson 6.1 95 nCode and now the 6.1 95 BLX (the first one).
I bought a 99s back in Feb, but didn't commit to it until about 3 weeks ago. I initially strung it with 16g Pacific Tough Gut in the mains and 4G in the crosses at 58/52. The gut was chewed up in no time, so I went with a full 16g 4G at 52lbs. Over the past 3 weeks, I've played 7 or 8 sets of very competitive 4.5 doubles. I also did a bit of drilling.
The good.
Overall, the 99s has been a real game improvement racket for me for the most part. It's easier to play with than the heavier, less manuverable 12oz 6.1 95. The biggest improvement is in my backhand and especially backhand returns, where I'm more consistent. Backhands are just easier to hit.
Serves were really nice with the 99s, especially spin serves. A lot more action than with the BLX, but not as forceful. Volleys were also very good. Overheads are much easier with the 99s than the BLX. Around the net, the 99s is a lot more manuverable than the 6.1 95 BLX, which I really like.
The not-so-good.
My forehand is my best shot. With the 99s, I really notice the less solid feel, less plowability as compared to the 12 oz racket. I didn't notice this as much with the other shots, however. Also, while my 99s forehand is not bad, it doesn't have the solid precision that I get with the 6.1 95. While I miss that more solid forehand, the other positive playability aspects of the 99s mostly make up for it.
The bad.
While I like the playability of the 4G poly, especially when freshly strung, my shoulder is slowly starting to have a lingering ache. I tried poly strings (mostly Big Banger) around 7 years ago with the result being that the poly really affected my shoulder to the point I had to give up tennis for a good number of months. My shoulder is starting to feel like it did initially back then. Since that time 7 ago, I've mostly used a nat.gut/syn gut hybrid. In fact, I think this is the first time I've used poly strings since then. I love the playability of fresh poly. I wish my shoulder can handle it, but it appears that it can't.
Another possiblity is that my shoulder achy-ness is also related to going from a 12+ oz racket to a 11+ oz racket.
Going forward.
Because I think the 99s requires poly, I regretfully think I need to move on from it. Where to go from here ?
I know I like the playability of the lighter 99s vs the 6.1 95, so I'm wondering if I should give the 99 (non-S) a try. With the the non-S, I could use my normal nat gut/syn gut hybrid string setup. If I continue to have shoulder issues with the non-S, then I guess that would tell me the lighter racket is a problem.
Any thoughts on that ? Any feedback on the non-S ? Has anyone successfully switched to the non-S ?
Another thought I had was to give the EXO3 Tour 100 a try. I haven't hit with a Prince for many years and never with their current technology. I was thinking of this racket because from what I understand, it would be lighter and more manueverable than the 6.1 95 and its supposed to be very arm friendly, though I don't have elbow issues, just the shoulder. Has anyone hit with the both the 99s and EX03 Tour 100 ?
Thanks for any feedback.