I spend more time with my Smiths than I do my Rugers, but the 3" GP's are excellent little guns indeed!
Do check the bluing closely, however, as the first one I received from Davidsons had a number of faint milky-colored splotches in the bluing. Didn't notice them until I had the gun a day or so. Admitttedly, you had to look pretty closely to see them, but once I did, they're all I saw. And I'm pretty picky about the condition of my guns. Fortunately, Davidsons replaced it immediately via their satisfaction guarantee (an immediate replacement policy, providing a replacement is available). I've used this guarantee twice before with a Puma .454 Trapper lever rifle and they're really great about it. Hopefully, you won't need to take advantage of their replacement policy, but make sure the gun is right before they sell out of their stock.
These little 3" GP's feel right between a 3" K-frame and an 3" L-frame... they're just a tad smaller than an L. The cylinder on an L frame is quite a bit stouter than the cylinder in the GP. With the little size GP grip, these are quite nimble and handy. I have a blue one and a stainless one and my favorite is the one I have in my hand at the moment.
Ruger GP-100 3" Barrel, Blue Steel, Fixed sights, .357 magnum (GPF-331)
Ruger GP-100 3" Barrel, Stainless, Fixed sights, .357 magnum (KGPF-331)
I've heard that Ruger is planning to install internal locks in their DA revolvers in the future, so if you want a nice GP without an infernal lock... start thinking about buying one now.
The only source that I know of for the blue GP-331's is Davidsons and they'll be out of them at some point with no more in stock available. Dealer cost on the blue one was $280 when I bought mine a couple of months ago. I paid $25 shipping and $50 dealer mark-up over that. My stainless one came from Jerry's, dealer cost was about $375, if I recall correctly. RSR had some stainless ones at one point, but told me they were to discontinue carrying them (not sure if he meant the 3" or all Rugers).