None, really.

Got some inherited and/or very carefully chosen vintage watches (1920s through 1970s) which I absolutely adore, each and everyone of them. Had one sort of miss-buy over the years, which turned out to be rather fragile mechanically, so ultimately traded that back (proper dealer). One or two still on wishlist, searching for a solid example, which takes time (no hurry there at all).

Also own a few new, relatively (but not overly) expensive watches, which I only bought after serious consideration and comparison to all manner of alternatives. Like those a lot, wear them when appropriate, no regrets. There are a few still on my ‘wishlist’ that may survive the ongoing pruning I do of that list, so which I may end up buying down the line.

And I own a good handful of micro-brand watches. These are predominantly for fun and novelty, and frankly cost so little that they do not interfere with anything else. I am slightly faster and looser purchasing those, but still only buy only 10-20% of what I come across and (fleetingly) like. So perhaps not that surprisingly, none of those have really disappointed: I know what I got them for and why, and that is exactly what they bring.

My only overall hesitance is the simple fact that in the end, the more watches I buy, however carefully elected, the less I get to wear each of them on average. First world problem.