My ultralight 317 3" was one of the very first firearms I purchased new (back in ~1998), as I considered it to fill its niche perfectly. This was going to be a 'woods' handgun I always wanted handy, but for serious range work I had other heavier options - so weight mattered more than anything, it needed to be minimized so I would tend to keep it at hand. IMHO it has no competitors, period. The 2" bbl version is isn't even in the same league - the adjustable sights of the 3" are absolutely necessary, much moreso than on my .38Spl service revolvers for example.
I am only a light user and confess to not shooting it very much. My initial experience with it was disappointing accuracy; but after some coaching from an experienced revolver shot (I'm certainly no novice in that regard), I found that it was considerably more sensitive to grip inconsistency than any other handgun I've fired. I know this sounds obvious in retrospect; but if you do purchase one, be prepared to possibly refine your grip technique. Folks do say that the S&W j-frames are difficult to master - I own three (love 'em all) and would only say that about the aluminum models. Most of my dry firing practice w/ those plastic 'wall anchors' has been done in my 317.
I also finally got around to testing a wide variety of ammo, and found that its POI varied considerably throughout the test (left-right as well as the usual up-down). Again, this makes some sense in retrospect, but its degree really made me take notice. From then on, I have been pleased with it now that I sight it in with a
specific 40gr loading and never grab anything different.
Unfortunately my ears have become rather sensitive to muzzle blast, and I have found that when firing HV ammo through my 317 it makes my ears ring slightly even when protected by standard earmuffs (this hasn't been the case w/ my 5.5"+ bbls). CCI SV is noticeably quieter through it than other commonly-available ammo so I now use that exclusively. An added benefit is that it is somewhat cleaner than most other 22LR ammo. I did test CCI 'Quiets' through it but found poor accuracy - IME a minimum of a 5-6" bbl is needed for the Quiets to perform consistently (and 10"+ is best).
If I needed to improve its' terminal performance, I would put a 0.180" deep HP into CCI SV w/ my Waltz die - I have had good success with that configuration in a few other firearms. In fact, I use this exact loading in my .22LR grouse rifle.
With regards to the functionality of my example, I have had no complaints whatsoever. I do tend to keep my firearms pretty clean, so have had no issues in the 20 yrs since I bought mine. By far the dirtiest ammo I've tried in it was Aguila 'SV' - firing that reminded me of a blackpowder revolver lol, that pairing was not a good one. With regards to the finish; yes it wears easily and I wish wish wish that S&W would have done a 35+ um black hard anodize finish instead. I have read reliable accounts that Hoppe's #9 will cause the 'worm trails' on the existing finish; so after seeing a little bit of that on mine, I now stay away from that.
The pre-lock ones demand a higher price of course; they are most certainly worth it as I have observed those models to continually appreciate in value while post-lock S&W's do not. I would not trade or sell my particular early 317, as the only satisfactory replacement would be another one, lol.