For me, I don't see the difference in sight radius between 2" (1.87", etc), 2.5" and 3" snub barrels offering me any noticeable advantage.
I do, however, consider the longer ejector rods you can get in 3" guns to offer an advantage in more quickly and surely extracting empty cases.
This doesn't come without a potential downside, though, because it may also create the opportunity for a displaced empty case to get bumped/dumped under the extractor, which can be a time-consuming stoppage to resolve. Fortunately, this is something that training to dump empty cases with the cylinder/barrel being held completely vertical can help mitigate (instead of just tipping the gun at an angle to push out empty cases).
I've also occasionally found that extra inch of barrel length in J-frames offered just enough better "balance" that it helped in both front sight acquisition upon extension and steadiness, and getting back onto the sight after muzzle rise. I remember my first M36, a 3" nickeled RB, was close to being as easy to shoot on our qual courses using 158gr LSWCHP +P loads as my M66 and subsequent M686 (both 4"), but then the shorter grip frames didn't bother me. I think the shorter trigger reach and stroke helped the comparison, too.
Anyway, for belt carry I don't mind the 2.5" and 3" guns, and my favorite K-frame is a M65/3", which I inherited with the passing of a longtime friend and mentor. I wanted it because he built it at an older factory revolver class, back in the days when they gave students a frame and matched yoke, and they had to choose all the other parts to assemble and fit into a properly working revolver to pass the course (and they could buy the gun at the end of the class). My friend was a former PPC shooter, and while he also used a Python in those days, he'd built some outstanding PPC wheelguns on K-frames as a hobby. I miss him, and getting that M65/3" makes me think of him every time see it (and the original box, which I have stored in one of my cabinets).
For my normal pocket-holster carry I prefer one of my many "2-inch" J's.
For the many years I carried an early Ruger SP101DAO 2.25", it was primarily relegated to a belt carry gun, as it was just too thick and heavy for most pockets. It even caused a favored and well-used stout insulated vest to droop on one side when carried in the outside cargo pocket. If i were going to get another SP101, I'd opt for the 3" model with a hammer, and use it as a belt gun. A bit handier than the 2.5" & 3" K's, riding around in a belt scabbard. For me, anyway.
Great to have so many choices nowadays. In older days we took whatever was on display in the gun store case, and were happy to have it.
A little later, when I knew a handful of cops who had FFL's, I was spoiled by being able to have them call their distributors and
find guns for me, which many gun shops didn't care to bother doing, even at the retial prices they charged, They just wanted to move stock. (And the discount pricing from my FFL friends wasn't a bad deal, either
)
Suit yourselves folks. You're the one who has to own it.
Sorry, but that's the bottom line.
