I have a late '70s/early '80s vintage Craftsman radial arm saw (model 113.19771). I prefer it over my power miter saw. The RAS has greater cut depth, a big table, and dust collection is far easier to set up. However, I know that these are on the lower end of the RAS family, and getting a used DeWalt or one of the turret Deltas would be a big step up in quality.
I have heard that there is a certain amount of variance in the quality of the DeWalts, with the round-arm models being the best, and quality tailing off over the years. My question is, was there ever a point that the DeWalts' quality tailed off to the point that a given model is no longer a significant step up from my current Craftsman? I've heard that any DeWalt (even the later square-tops) with the elevation crank mounted at the pedestal are still a significant step up from what I have, but DeWalt quality took a hit around the time they moved the elevation crank to mid-arm. At what point along that continuum (if any) should I judge that there's no longer a significant quality improvement over what I currently have?