I have had more of a chance to use this ball lately, and all I can really say is WOW. This ball is probably the best kept secret in the bowling industry. If I had not sold all of the ones I could get online here, they would have sold themselves just from people watching me throw it.
This ball does exactly what I wanted it to do. I fits just under my Thrash. It goes about 3 ft further, but when it turns left it turns so quick there is not time left for it to turn on its turn signal----then SMASH. The Darkside hits harder than my Thrash, my Dynothane THING, and almost anything I have right now. If you try to use it in oil though, this thing will hit like a marshmellow.
For me, with my ball speed this ball will absolutely not move in oil. I have to have fresh backends for this ball to work. For the normal league bowler, considering the normal house shot, and the average speed, this ball is the ticket.
There are still some out there to buy, and for the price, pro shops can let them go very cheap. Buy them up while you can.