I carry an L-frame for now. I've often considered the 27-types. What I know about them is there were several iterations which can be classified as
* Registered Magnums - the first ones, fetch a high price because of their exclusivity and value to collectors. They had individually customized features. Although they're pricey, they won't lose value like the new ones. If I bought one, I'd never want to sell it, so it would require me that I tie up all that cash permanently. It's as good as gold, but gold would be easier to part with.
* Post-war 5-screw - most of them were produced under Carl Hellstrom in the 1950's. I believe these to have the most consistent quality after the Registered. There were several barrel length options including 3 1/2", 5", 6", 6 1/2" and variations a little over 8 inches. Some early ones may have had the non-Magna service panels, but most either have the Magna-style grips or Target grips. There are also models with Target hammers and Target triggers. I've not used those, but I'm skeptical of them. I doubtful that I would like them.
* Bangor-Punta era 27-2 - I'm skipping over a lot of minor variations here, but clearly things changed when the Wesson's sold out. I think there are some outstanding 27-2's to be had, but believe the quality became less consistent under the new owners.
* Post-P&R - Again, I'm not trying to detail all the dash- changes, but clearly once they stopped both pinning the barrels and recessing the cylinders, the product was different. There are some interesting models from this era including stainless-steel Model 27's. The ones I'm talking about here are all before the current Model 27 "Classic" or the stainless 627 (which had a version introduced in 1989 and then the current version).
* The current Model 27 Classic - Earlier, there were also some 2nd-generation "Registered Magnums" and 8-shot blued model 27's. These benefit from modern production processes that could give it consistency in quality that was lacking in some previous eras (where some guns were great, but others not). I'm cynical toward current production quality because of considerable bad experience with multiple current production S&W revolvers (but not 27's). The other thing about the new Classic models is they use the current style sights. All previously produced model 27's use sights that are no longer available and can be difficult to replace. The current style on the Classic models has full support of the S&W factory and lots of aftermarket support. I've handled the 4" version with the Magnas (made to look like the original 3 1/2" guns) and the 6 1/2" version which notably comes with (3T's) target grips, a target hammer and target trigger -- a super-wide, flat-pad, serrated trigger (not sure I'd like it). The 4" version comes with the regular hammer and trigger.
For me, I believe the best bet would be an early 5-screw with the barrel length, stocks, and triggers that I decide I would like. But I see them consistently going for $2000 or more nowadays. Later model 27-2's in comparable condition can be had for about 25% less.