I'm trying to not be argumentative as sorta like a New Year's resolution. So, I'll just say that your Rogers set must have been a rare exception to the greatness of the Swivomatic era Rogers drums. Swivomatic hardware set the bar very high for drum hardware. Its ball and socket principal is still copied by many drum manufacturers. Rogers raised the bar again with Memrilok tubular-type hardware which is also still copied by other drum makers. I was not a big fan of Dynasonic snare drums mainly because it took way too much jacking around with too many adjustments to get it to sound as good as many simpler snare drums. I also prefer a wood shell snare drum.
For me the problem with the swivomatic hardware is that it just did not hold up well. The drums were used when I bought them, I guess they were 5-7 years old, by then they would not hold position very well and it was agonizing to loosen and tighten the part that connects to the drum. Basically they were worn out after just a few years.
I feel it should last much longer, I have 50 year old MIJ hardware that still sets up and holds position like it was brand new. For a high end drum mount system to wear out so quickly is in my view uncacceptable. Now I can't say what abuse the previous owner might have put them through, all I can say is that by the time I owned them, they were certainly still usable but problematic.