The guy who runs the company has a long thread at MyYY here: http://mytabletennis.net/forum/forum_po ... ary#904078
and down the thread from there. Pretty interesting reading, although the first time I read it I was skeptical. But a few people like Next Level and ViktorK had good things to say about these rubbers, so I got curious.
For the last decade, I have played more or less exclusively with ALC blades and either Tenergy 05, or most recently, MX-P. I am a conventional two wing shakehand offensive player, getting older now, but still around 2050-2100. These days I have worried that I have had a tendency to beat myself more than I would like, missing shots from mistiming -- a lot of that secondary to not being as quick as I used to be (and maybe needing new glasses). I don't like my level dropping. It is inevitable but I don't like it.
So I bought one sheet of Karis M and one sheet of Karis M+ (harder sponge) in max thickness. I have used them on a ZJK-ALC (basically a Viscaria with a ST handle). Again, note that I actually paid full price for the rubbers and have no connection to the company and am therefore a more or less unbiased observer (or if anything, I went in with a negative preconception).
Here is what I have noticed so far with these rubbers:
There is a slight dome of the rubber right out of the packages (true for both M and M+). The sponges are blue color with very thin pores. There is no booster smell, in marked contrast to MX-P. I had forgotten how much easier it was to glue down and cut rubbers with thin-pore sponges like this one. A very nice feature. They are about teh same weight as MX-P. (M+ is a little more but not enough to worry about).
The pips on the inside of the topsheet are incredibly short (I've never seen anything like it before) and they have a shape that is somewhere between a circle and a hexagon. The topsheet therefore, overall, is very
thin. I think this may be the key feature of this rubber. (I hope it does not make the rubber fragile).
These rubbers are not real fast, and not unusually spinny (although they certainly spinny enough and the topsheet has a very nice grippy feel). The main thing is that they are incredibly predictable
, which became clear to me within a few minutes. That is the thing Nexy talked about in his threads on what he was trying to achieve when he developed the rubber. I have to admit I was very skeptical about that when I read it. It sounded like BS to me. (His threads always made me wonder).
But having tried Karis, I now think he has accomplished what he set out to do, and his descriptions ring very true once you try this stuff.
I'm not just talking about his descriptions of Karis, but also how Karis is different from Tenergy and recent ESN rubbers. When you play with Karis, you sort of feel what he is talking about. These rubbers are really are something novel I think.
More than anything than, I would say the main features of Karis are predictablity and linearity. (Output is directly related to input with no weird discontinuities to put it in more quasi-technical terms).
Because of the predictability of the rubber, I was able to keep the ball on the table really well tonight. When I wanted to hit slow, the ball went slow, and it went where I aimed it. When I swung harder, the ball went faster, and importantly, no sudden increase in ball rebound with a slight increase in racket speed. (That is in marked contrast to the MX-P). So very few inexplicable misses where you hit the ball off the table and you're not sure why. With that said, they don't feel like Chinese rubber to me (I don't like those). Different. Not sensitive to spin particularly. I would not call them either Euro/Japanese or Chinese. I think they are something new.
One of the places this really showed up is against my opponent's good shots. I brought a lot more of them back and lived to battle longer in the point. I think most amateur offensive players will find that they are a lot better when they are on the defensive with this stuff than they would be with a lot of popular rubbers. In general I kept the ball on the table, but I also felt like I was able to be a bit more deceptive as to where I was going to place the ball. In other words, make it look to opponent like I am going to drive the ball crosscourt with my forehand but then go to the body or down the line at the last minute. For some reason, that was easy with this stuff. Also I was hitting really good angles and I was looping with a lot more variation in pace.
For now the only downside, and I think it is temporary, is the sense that some of my shots lacked the penetration I would get with Tenergy or MX-P. That's to be expected, Karis is definitely slower than either of those. Also, it seemed like I was hitting my forehand flatter than usual, probably subconsciously trying for more power to compensate for speed of rubber. I guess I would say that the throw is medium, though. I will need to play more with an eye on that more. In any case, when I got good body rotation that was not a problem, then the ball had plenty of pace. It is better to keep the ball on the table and win more points than it is to look spectacular winning a few points, so I don't mind. This sense of very linear control was present on every single shot. Loops, counters, blocks, short game, serve, return, push. I will need to work hard to get good body rotation on my opening loops in particular, because this stuff definitely does not reward lazy technique. You don't need to be Ma Long b ut you can't just loop with your arm. If you do, it will feel like it is about to fall off in a couple of minutes and your shots will suck!!
As for M vs. M+, given what I have been playing with for the last decade (T05 and MX-P), M+ is a step too far, especially away from the table. I definitely preferred M. Actually, for now I am more comfortable with M on the FH side and M+ on the BH side (which is a bit odd since M+ is distinctly harder), but I plan to use M on both sides for awhile and see how this goes. I ordered another sheet of M today so I will have it on both sides.
People will probably ask me to compare with all sorts of inverted rubbers. I won't be of much use. About the only ones I know anything about are Tenergy's and Evolution MX-P and EL-P. Karis is nothing like any of those.