I'm not aware of any quality issues with the stainless steel used in Case's knives in the '80s, in itself. But, through the '80s and up until the mid/late '90s or so, Case's blade & edge grinds seemed different to me, as compared to post-2000 and current-generation knives, which seem to be done better (thinner grinds, more acute at the edge). I started accumulating new Case knives in greater number in the '90s, and had noticed many of the knives of that era had edge grinds that I really didn't like very much, and needed more work to get them thinned out and cutting the way I preferred. Around ~2000 or so, I seemed to notice an abrupt improvement along those lines, and began to favor those later ones more. I made a few exceptions for '90s-era knives with other attributes I liked, like really attractive handles, etc., and maybe some limited-run knives that I otherwise wouldn't find at all. But for the most part, I tended to avoid them.
There were some other minor aesthetic issues with the '90s-era knives that I didn't favor. For one, the Case 'oval' shield of the '90s time frame took on a slightly more blocky/blunt shape that I didn't like, as compared to the more streamlined & elegant oval of the earlier-era knives. But that was a subjective thing, as viewed in my own eyes, and not really an issue of fit/finish or build quality.
In terms of general heft and sturdiness from a user/functional point of view, I've seen NO difference at all, between the '80s & '90s knives and those of the current generation.
