Case by case, record by record. I buy old pressings 10/1 over new ones. I have nothing against reissues or remasters as such; some do actually improve on the early or original pressing (whatever you want to call "original" also varies); some are obviously inferior sonically to early pressings. First pressings aren’t always the best sounding ones either.
I typically buy a reissue when the original is so costly that I’d likely not buy the record at all, given the price.
As to the gear, yes, agreed, we live in an age with more turntables, arms and cartridges than ever. But, some of that vintage gear is pretty killer too- the EMT tables, the refurbished SP-10, Micro-S, etc. I don’t think there is a single answer to any of this. In my case, records I have owned for 30 or more years sound better now than before because my analog front end has improved over time and, with respect to old records, as @lewm and @terry9 noted, knowledge about record cleaning is better and my methods and equipment have improved. (The Monks, which is essentially the same now as it was in the late ’60s does a very good job, as do ultrasonics, with some limitations in my experience, a subject for another thread perhaps).
To come back to the records, there are some terribly recorded, mastered and/or manufactured records from the ’60s and ’70s, just as there are such records today. You’ve got to dig in, trade listening notes with people you trust rather than rely solely on reviews and go through the experience of comparing pressings of records you like. My biggest complaint about audiophile pressings is that for obvious business reasons, the same stuff gets reissued again and again. The obscure, harder to find stuff is often not reissued, or is reissued "unofficially" (read: counterfeit or bootleg) and when it is legitimately re-issued in many cases, it is not by an audiophile label, source material is likely a digital file (not that this is always bad, but...). Occasionally, a good reissue label will do a bang up job on something that is not a warhorse but I think those are exceptions.
To me, this is half the fun of having records- the research, the comparisons, the history behind the recording. The real grief in old records, apart from sorting through the thicket, is condition. That is also a subject for another thread (about which there are already many).
