My first set of Crimson Trace grips came on an S&W 637 (the Airweight version of your 37) seven years ago. At that time the only grip available for J-frames was the 305, the full length grip with the covered backstrap. Now there are three different versions, the 105 (hard polymer grip with no backstrap cover -- a great blister maker, with pinky adrift in space), the 305 (rubber grip covering backstrap -- still a pretty good blister maker, pinky happily involved), and the 405 (rubber grip which covers backstrap and also provides a "shock absorber" right where it is needed to prevent blisters, pinky adrift in space). The full length of the 305 grip make it slightly less concealable in pocket carry than the other two, but in the trousers I wear (slacks, not jeans) I have no problem with that.
I now have CT grips on my Browning Hi Power and S&W 686+ as well. In all three cases, the CT grips, simply as grips, were at least as good (the 686+) or better than the manufacturers' grips. All are activated and deactivated quite naturally, almost unconsciously. I would not buy a handgun that cannot be fitted with a set of Crimson Trace laser grips. For me, that is a fatal flaw.
CT grips are not suitable for busting bowling pins at fifty yards in the noonday sun. They are designed for self-defense/home-defense situations, and for these purposes they are outstanding.
I might add that I am impressed with the volume of responses to this query, made this day -- all favorable. Where are those who say laser sights are evil, or at best an answer to a question never asked? Have they been silenced?
Cordially, Jack