I've got a 97 B which I had CGW mill to place my JPoint on. I also have an SW Shield Plus in 45 which came with a Crimson Trace, which, surprise, surprise is identical to my JPoint! Looking at a number of red dots prior to my original JPoint purchase, it appears that many have the same base. Perhaps the internal electronics are the differentiators.
I've found that placing my trigger finger on the weapon such that when I draw I'm pointing at the target minimizes the time to acquisition. Practicing that with dry fire at home makes range time much more useful.
For dry fire I've purchased one of those cheap chambering lasers which fire when the firing pin hits, along with a cheap laser target which lights up and counts hits. I've found a pathway in the home which is about 10 yards. The active area of the laser target is about 1.5" in diameter. It's really tightened up my groups at the range.