As of October 27th, the Nittaku 3-star SHA poly ball is the official ball used at the Samson Dubina Table Tennis Academy. 
 
In my opinion, the ball seems slightly softer with slightly less spring than the celluloid ball.  It is clearly easier to serve short serves and it is somewhat easier to block loops.  However, when blocking a very high speed loop, the ball sometimes seems to wobble.  The same is true when smashing at a high speed – especially when smashing flat (without spin).  When smashing with spin, the control is very similar to the celluloid ball with about 5% less speed.  When smashing flat, the control is reduced significantly.  In addition to the reduction in speed, there is also a reduction in spin on serves, loops, pushes, and other shots.
 
So how will this change the game?  I feel that the power loopers will need to be physically more fit to play longer rallies.  For the spin loopers, I feel that they will need to focus on other areas like height and depth variation instead of merely counting on spin.  I also feel that the defensive players will have a slight advantage because the balls will be slightly slower.  I also feel that blockers will need to learn to add more topspin when counterattacking.  I also feel that there will be more short serves and short receives.  With the celluloid ball, many serves and pushes were intended to be short, but actually went long enough to loop.  With the slower ball, many pushes and serves will likely be shorter and much lower.
 
So what should you do? 
 
#1 Change to the poly ball asap.  The world has already changed to the new ball and many players have already played poly ball tournaments.  Don’t be left behind.  The sooner that you change, the better.  Make the adjustments now and you won’t be making those adjustments later.
 
#2 Add more variations in your game.  With a reduction in speed and spin, try to find other ways to win points by adding more tools to your toolbox.  Instead of winning the point with your first smash, you need to find ways of working the point with creative, deceptive shots.
 
#3 Stop thinking about it.  Don’t blame the ball for every small mistake.  Within about 3-4 months, your game probably won’t suffer too much from the ball.  The more you dwell on the fact that you like or dislike the ball, the more you will be distracted from your real focus.  Your real focus should be on developing your game – not crying about the ball.