The 'pinned barrel' was the way Smith & Wesson made their revolvers prior to 1982 or so. Since that time, the barrels have been 'crush fit' or simply made a trifle oversize and forced to fit. Along with 'pinned barrels', they used to recess the chambers on their revolvers chambered for Magnum calibers and rimfires. (The .32s and .38s and such were never recessed. I believe the oddball was the .22 Jet, that was also recessed; it was based on a .357 Magnum case.)
Most of us old guys find this 'change' in manufacturing protocol to be cheapening and resulting in a less graceful and shoddier product. In fact, S&W had some problems with their early 'crush fit' barrels unscrewing of their own accord. I understand that is no longer a problem. Another criticism of the crush fit system is removing the barrel for change or adjustment is difficult.
The 'lock' came sometime after the crush barrels. It was a 'safety' feature heavily suggested by the Clinton Administration - for the children, of course. S&W agreed to the 'lock', then got some serious government contracts - this was widely seen as a sell out. The locks do nothing to enhance the safety of children and - while heavily denied - have been found to switch on under heavy recoil. This may also have been 'fixed', but it's too late for me.
I really appreciate Smith & Wesson revolvers and own - uh - several. However, I refuse to buy any new ones; they are simply cheap copies of Smith & Wesson revolvers.
For a general use revolver, they are probably acceptable. Many people have bought them and appear to be happy with them.