Six years ago I sold my tackdriver MKII - and bought a new 4" 617 - instant nirvana! A year later found me buying a late friend's NIB 5" 63 from his estate. No contest - the 617 was still my favorite. Then, a year later, my long awaited new model - 3" x8 63 - arrived... and hogged the range bag. The next year found me at the range with a friend and his new 4+" SP101 (x8 also). We A-B-ed them - the 63 had the better trigger (It was a year old then, so that was expected!), grouped better, and aimed more naturally ('Pointed' more readily.). He bought a new 63 - no new Ruger here.
One of my 'bucket list' finds was a LNIB 4" 651, basically an older 4" 63 in .22 WMR. Here are my two newer 63's - and the 4" 651 between them. You can pretend the 651 is an older 4" 63 - they do look identical. The grips are S&W '60 Pro' style - my favorite J-frame grip.
If I had to say goodbye to all of my rimfire firearms, long and short, save one... I'd keep the current production 3" 63! It fits the S&W 3" holster, as does my 3" 60 Pro. I also have a DS-10 speedloader & loading plate for it (...and the x8 5" 63!). It loves Fed 550 pack and AutoMatch - and can dispatch a brick of either with no unloading/reloading problems. CCI Stingers are another matter - sticky extraction begins after the third cylinder full - but that seems consistent with my other 5" 63 and 4" 617. The HiViz sight really helps fast target acquisition with mature eyes.
I tried a lighter hammer spring in the 5" 63 and 4" 651, but misfires caused my reversal there. The 3" 63 is box stock, followed by the 5" 63 with spring changes and trigger/rebound slide clean-up, my box stock 351PD, and, the most stout J-frame DA trigger - my 4" 651. I've shot older 63's & a 34 - they were all nearly as stiff as the 4" 651, which is stiffer than the 3" 63 by a bit - but still very usable. I'd get a new 3" 63 without reservation. If you find a fault, S&W will pick it up, repair/replace it, and return it on their dime. I had to send my last new S&W (1/13 - reported here.), a 351PD with a poorly made extractor star (It skipped two empties!), back. No problem - and 'stuff' happens. First new S&W here that had to go home due to a QC issue - after two dozen new S&W's - still a new S&W lover... IL, MIM, etc and all.
Stainz