I own two Dan Wessons, both M15-2s, both "Monson". I purchased my first one, with a 6" vent rib barrel circa 1977. It was my only CF handgun for several years. The Lord alone knows just how many rds. have been through it. The vast majority of them have been my cast bullet handloads of various flavors. It shows some miles on the outside, but it still locks up tightly and hits where it's pointed.
I've experienced exactly one part failure: sometime in the late '80's the pressed-in cylinder stop lug on the frame came off while I was shooting the last of a few boxes from a lot of PMC-made factory 158 gr. JHP's I'd purchased. IIRC, they'd seemed to me to have been a good bit "warmer" feeling in both recoil and report compared to other factory 158 gr. stuff I'd used.
Anyway, I called CS at DW to see if I could order a new part to be installed locally or if it needed to be sent to them for repair. Even though my factory warranty had long ago expired, I had the new part and detailed instructions for its installation in my hands within a week and the shipping invoice read "no charge".
I felt compelled to write the company to express my thanks and appreciation for the courtesy and consideration the CS rep had shown me. A couple of weeks later, I received a letter in return, hand-signed by D.B. Wesson himself, and an embroidered Dan Wesson Arms patch thanking me for using their product!
When the company unfortunately had gone OoB, I purchased several barrel/shroud combos and an assortment of action parts (from CDNN, IIRC) against the day when I might need replacements. So far, only the barrels and shrouds have seen any use and all of them have fit and functioned perfectly on either of my relatively early production revolvers even though the parts themselves differ in several respects from those that were OEM when they were produced. FWIW, the later model barrels with a much different-looking rifling pattern seem to display, for me anyway, a tad bit better accuracy than the originals.
