The older guns are generally finished better and are devoid of MIMed parts, which are unsightly to some and may not wear as well as forged ones. On the other hand, the new guns have been improved in other ways. In the 70's, which is when I bought my first Smiths, both S&W and Colt had QC issues that resulted in guns going out the door with serious functional problems. Some of those guns ended up in the holsters of police officers and the service departments were pretty busy. The cops had priority for service and regular folks often had to wait a bit. I had two guns from that era, a 29 and a 17 but the only trouble I had was occasional DA misfires with the .22. A new mainspring, installed locally, fixed that.
I have two Smiths now, one a 620 L frame 7-shot .357, with the two-piece barrel, MIMed lockwork, round butt, and the dreaded keylock. It's a fine shooter, with a super crisp single action pull, and has functioned perfectly. I don't carry it much, due to the weight, but I like it very much and someday hope to get one of the Pro Shop guns in the same configuration but with the forged lockwork. I generally ignore the lock, but as noted earlier, find it useful on occasion to secure the gun short-term. The other is a 642 .38 with S&W/CT laser grips that stays with me pretty much 24/7. That one came without the lock. Both guns were purchased used, but LN. Both guns are giving me excellent service even if they're not quite as shiny as ones made in the good old days. I buy guns to shoot, not admire (well, mostly).
I can take the keylock or leave it. It's an unobtrusive, and in my experience, a well-engineered response to the current market and legal situation, and not, I think, a political statement or philosophical sell-out. I'm certainly not going to let its presence, or lack of it, deprive me of the enjoyment of the best DA revolvers on the market. I get more enjoyment out of shooting than I do out of being offended.
