KGP141 here... if I had to do it again, I think I might have gone with the 6". At 41oz- nearly 3lbs loaded- and given it's dimensions, I realize now that any possibility of carrying it was pretty unlikely given my lifestyle. So as a dedicated range gun I'd probably prefer the longer sight radius and a little less flash that the 6" barrel provides. I've not handled one, though, so I'm not sure how a 6" balances (I know that the 6" S&W 629 handles like a dream) because the 4" balances nicely but is already a
little muzzle heavy.
The entire gun locks up very tight (no cylinder, hammer, or trigger play AT ALL) and there's only the slight rattle of the transfer bar when the hammer's down. This gun is
solid and really evokes the emotion of durability.
DA was hard and a little gritty at first, but is easier now (whether because of experience or because it lightened, I do not know, I suspect the former) and only
slightly gritty now (surpassed in smoothness only by S&W M18-4 that's older than me, in my collection). Shooting Double Action only rapidly, I've found it possible to keep my rounds on target. SA is extremely crisp, rivaling my SA-only autos even, but a little heavy (4-5 lbs)... you can be very very accurate with this in SA.
My brothers and cousins have fired this as their first .357 ever and all have found it to be accurate, controllable, and great fun. The look on their face the first time is priceless and for that reason alone- those memories- I'll never sell this gun. The weight and power of firing their first "real" gun.
I love that its over-built, has no lock, and real stainless finish (as opposed to the strange grey of some of the late-model S&W stuff). The ejector rod shroud is OK styling, but I could live without another nook to clean. The ease of replacing sights is great. The grips are great, the only revolver grips that I've never replaced... and I'm sure it's a taste thing, but I think they look great.
I personally, have never had a failure of any sort, but my friend using the same gun has had it bind and seize on him. The first case was because he didn't work the ejector rod with enough force after shooting .357 after .38 (without cleaning in between)... it got stuck halfway and the casings had to be pried out with pliers. The second case, we never figured that one out... he said he couldn't get it to turn fire, handed it to me and everything seemed fine, opened the cylinder, closed it and cycled through/fired all the chambers. I mention these only to say that I was 100% calm and had 100% faith in the GP100 despite these "problems". I don't really know how to express this intangible feeling any other way. If the same had happened with another revolver, I know I'd immediately begin to worry if the gun was compromised (out of time, bent crane, who knows?). Irrational- yes- but a lot of gun ownership is emotion (especially range guns) so I thought I'd throw that in there.
Wow, more than I intended to write, but I think that about covers my experiences.