^^How much truth is there about these balls causing Arm trouble or Arm injury ??
Different strokes for different folks. I can tell you the one time I popped out new MicroX balls with advanced open players, they all but walked out on me on the spot because they said...WTF!!! these balls are hard as rocks, I can feel it in my elbow! ...that and the balls were bouncing like superballs and practically bouncing over the fences by themselves. ...add also that they felt as heavy as bricks.
This said, *I*, *me*, *personally*, didn't think they felt THAT bad. Heavier, bouncier, and noticeably harder on the elbow? All absolutely true for me too, but not THAT bad and I thought it was a worthy trade off for the price.
Compared to Gamma pressureless balls, they're LESS hard (now THESE balls feel like you're hitting with rocks), noticeably bigger (heck, they're also noticeably bigger than a standard pressurized tennis ball too, kind of like how the Dunlop Grand Prix balls are slightly bigger as well), and have a much more realistic ball bounce/playability/LIVELINESS.
This said, the MicroX balls after a few hitting sessions, they tend to break in. After this initial break-in period, then they start playing very much like regular pressurized balls and no longer have the "superbounce" problem and also don't see to jar the elbow as much or as heavy. That's the main thing about them when new, they feel like the heaviest balls against the racket face I've ever felt. It almost feels as if they push the racket face around rather than the other way around.
The other thing to note is that according to the US distributor, the balls sold by the tube/can like I bought are noticeably more lively and jumpier than the balls sold by the bucket in bulk. The reason he said is something about when they're packed or something I think he said. The ones sorted off for the bulk sets are picked off later during the production one or something. ...eh, actually, I don't really remember what the reason is, but the bottom-line was that he told me the balls sold by the bucket don't have OVERLY bouncy problem of the individual tube sets.
This said, the MicroX balls definitely do tend to lose their bounce the more they're used. They'll reach a point when they bounce about as much as one-two week old pressurized balls. In others not totally dead or flat, and still playable for practice; but you wouldn't use them for a regulation match by any means. They tend to level out once they reach this stage, and just stay there until you lose them or they eventually explode on contact when the casing has seen it's last days (I lost all mine before this could happen, but that's what others have reported eventually happening to some of them).
Personally, the best pressureless ball to me are the Unique Sports (makers of Tournagrip) Pressureless balls. Not only are they way cheaper than the MicroX balls, I think out of the box, they play near identical to pressurized practice/"x-out" balls. I've used them with former low-level pros, and they never suspected they weren't regular pressurized practice balls until I told them. Their immediate response? Where can I buy them!
In other words, they passed the blind sniff test.
I was tipped off to them by a teaching pro who said they play and FEEL more like pressurized tennis balls than any other pressureless ball he'd tested (and he'd tested them all, trying to find a reasonable solution for his clinics, drilling balls).
He was right imo.
This said, that was a few years ago. I have to say that more recent batches I've bought while still having the same general feel, weight, and size as pressurized balls; they've seemed to bounce noticeably less than they used to. It used to be that when I "drop-bounce" tested brand new pressurized balls next to new Unique pressureless balls, they would bounce up to pretty much bang on the exact height...no more. The last few batches I've bought bounced up not a lot less, but noticeably less.
Still, they do NOT jar your eblows the way Gamma and Tretorn balls did from my experience, and they still bounce and RESPOND the most similarly to pressurized balls I've tried. Add that at their price, they feel almost disposable compared to the MicroX balls, they're to me a no-brainer.
Imo, they don't hold their bounce quite as long or as steadily as the Micro-X, but they're noticeably easier on the arm, are way cheaper that you can afford to continually "freshen" up your batch, and they bounce and feel more like "real" balls.
The thing with pressureless balls is that it's NOT true that they hold their bounce indefinitely. When they've been around the block one too many times, they DO definitely start to lose their bounce. The difference is that they eventually hit a point in their life cycle where their bounce no longer declines and at that point it'll kind of just stay there. This just "stay there" state is still MUCH better than worn, dead as a pancake pressurized balls. In other words, a little low bouncing, but not so much so that they become virtually unplayable and you feel like you have to scrape your bumperguard off the court to reach balls.
