Jpuke
Years ago, under a different ownership (Clinton era), S&W entered into several controversial agreements with the Govt. That were seen as caving in to the anti-gunners. I believe this was done in a misplaced effort to stem the tide of product lawsuits that were prevalent at the time, and were threatening to put a lot of gun makers out of business. It left a bad taste in a lot of shooters mouths.
Another complaint with recent S&W's is the inclusion of "the lock", the use of frame mounted firing pins, and the use of MIM parts (trigger and hammer) on most models.
As far as the lock goes, no I don't like it, but it is getting to be a fact of life these days if you want to be able to sell your guns in all 50 states, and want to avoid lawsuits. More and more major manufactures are now incorporating them (Ruger, S&W, Taurus, Walther, etc.)
Handgunners tend to be a conservative bunch, and resist change. When S&W stopped using pinned barrels and recessed chambers, you would have thought the world was coming to an end. I'll bet an earlier generation of shooters cried S&W was going down hill when the triple lock was discontinued.
Fact is frame mounted firing pins work just as well, and are a proven design in such highly regarded weapons as the Ruger Redhawk series. While admit I like the looks of case hardened hammers and triggers of old, I have not really seen any reliable data showing the MIM parts are significantly, if at all less durable. Non-recessed chambers have proven just as strong as recessed, and more reliable as there is less chance of crud accumulating under the rim that could jam a gun. The "Endurance Package" incorporated into S&W big bore revolvers in the early 90's has made the lock work significantly stronger, allowing these guns to stand up to repeated use of heavy loads much better.
I have owned about 25 S&W revolvers over the years, mostly big bore N frames, and have always found them to be quality guns. Two years ago, I bought a used S&W 629-6 4 inch .44mag revolver with "gulp" - the lock and MIM parts. It has as good a double and single action trigger pull as most any other N frame I have owned, excellent fit, and one of the tightest lock-ups of ANY Smith I have owned. It shoots 1 to 1 1/2 inch groups at 25 yards with loads it likes, and has proven to be 100% reliable, with at least 1000 rounds thru it, a lot of them heavy loads.
The Rugers are fine guns as well. I have a couple Redhawks, and am quite pleased with them. I do like the style and feel of the Smiths more, but that's subjective. Ruger does not make a .45 acp da revolver though. Unless you are willing to possibly have to work the fixed sights to POA for one load, I would consider adjustable sights for their much improved utility. Good luck with whatever you choose.
Larry