I had my first 3 hour session with it last week. I'll paste in my initial feelings from another forum:
First thing - my sheet isn't perfect. The sponge has a few pits, and the topsheet has some lumpy bits - not quite bubbles, but close. A determined tournament official would probably disqualify the rubber for not being totally flat.
That aside, it's an interesting rubber. The topsheet is semi-tacky (lifts a ball for half a second), thin, very soft and pliable. The sponge is porous and medium-hard. There is a slight dome, so some signs of a factory boost, but no particular smell.
Close-in control is excellent, spin on serves is very high, and it's very easy to keep the ball short. It has a far more elastic feel than old, traditional chinese rubbers for sure, and the medium gears are great for controlled looping and general topspin from over the table or medium distance. It lacks speed in the high gears, so blade selection is important if you play from distance (or you could boost it some more I suppose). The arc is a solid medium and feels very stable - I felt that counterlooping was particularly good, with a very safe feeling.
In terms of gearing, the lower tack on the topsheet helps to avoid the feeling of the ball holding up too much on most shots, but the general lack of bounce means you have to put more forward motion into flicks and punches when dealing with slower balls. This is a common problem with these types of rubber (H3-50, Big Dipper, etc have the same kind of response), but STN does respond well when transitioning to more of a brush from a flat shot so you get far less off/on gearing.
I liked it a lot. QC is a bit of a worry at this point, so I might buy another sheet and see how that compares. It feels like an evolution of the hybrid approach seen on Big Dipper - modern, porous sponge with a semi-tacky topsheet. There are a lot of these types of rubber on the market now, but this is one of the better ones. This one does feel higher quality than, say, Big Dipper overall - a more complete package, better general feel (very smooth with less cheap, junky feel). It feels closer to Rising Dragon than Big Dipper in reality, but the topsheet is softer and more flexible than both. I know people want to compare to boosted H3N, but I actually feel that STN is closer to a mildly boosted Skyline TG3 Neo 38 degree.
