I have really enjoyed throwing my Gemstone in the month or so I have had it. I wanted a ball that wouldn't react early--later down the lane much like my Lane#1 Bullet, but would have a bit more movement on the backend. Since I lack versatility as a bowler-----if I cannot sqaure up and play a down and in shot , I am like a fish out of water--so I have been struggling for better than a year to score on the new lanes---much cleaner backends, and lesser volume of oil my home center puts out.
Since I have gotten my Gemstone, I haven't had to fight the lanes on nights when the oil is really light, which seems to be almost every week seemingly. The Gemstone gets really good length before it does it's thing, -- I was hoping that Lane #1's assesment of the balls backend strength were exaggerated or incorrect, and that the ball would be a bit milder, as I read in the reviews and forums here about the ball before I bought it. Unfortunately, Lane #1 was spot on about the backend strength--it definately has movement on the backend, but not soo much as the Columbia jekyll I had, which was very much skid snap type of reaction. However I was able to tone down the reaction on the back to suit my needs through tracks delayed reaction and the drilling.
The thing I noticed my first league night with the ball was that it really kept the pins low and spinning. As far as the hitting power goes---I was a bit skeptical about that when looking at the core shape, but decided to take a chance anyways. The hitting power was certainly more than I was expecting from a core like that---certainly not harder hitting than most of my visionary stuff I have owned, but more than I was expecting. carry was good--the rack didn't really shatter, but the low spinning pins took out pins late that should have or would have remained standing. The majority of the time I was close to flush in the pocket, the result was a strike.
2nd week---carry issues, mainly due to bowler effort error-- to lazy or stubborn to adjust my approach for that--3rd week got wise and adjusted on the approach and carry issues were not an issue.
The main drawback I see is that if I make a physical mistake with my release--not talking targeting error here--but just physicaly not correct on the release, the ball won't cover for me. I do recall leaving a couple of pocket 5 pins on bad releases, and I have left a pocket 7-10 with this ball.
Overall this ball is perfect for me right now---it allows me to square up and play down and in on dry lanes without an overreaction on the backend, but more movement on the back than lower differetial cored balls, like my Lane#1 Bullets. So far I am a satisifed customer.
Brad