Well, you just have to decide if the story is truly the best in the category -- and I think "overall enjoyment" ought to feature heavily in your choice. I'd rather read a wonderful story by an author who has a few rough edges than a boring clunker that's gramatically perfect. The "wonderful story" part is what should be encouraged, IMO. Technical writing skills can always be improved.
There have been many times when I've thought a story was very well-written but I didn't really enjoy it, for whatever reason. That's not "best" for me. And I always figure, there are probably other people out there who really love that kind of story, so it'll do fine, with or without me.
I also noticed that established authors had a distinct advantage for my attention. Diving into a story by an “icon” is easy, I have a fairly good idea what I’m going get and that I’m not going to be disappointed. Reading a story by miss No-name OTOH had elements of a chore. The first time I discovered that I simply skimmed some of them to be able to eliminate them.
But then on the *other* other hand... reading a story by a new author can give you such a breathless "wow" feeling precisely because you *don't* have a fairly good idea of what to expect. That freshness can be invigorating.
Also, if there's a well-known author whose stories I haven't really been keen on in the past, I will be less likely to try the latest one -- even though it might be fantastic and I'd love it if I read it.
Even with authors I tend to enjoy, it's easy to stick them in a box -- a feeling of "been there, done that" -- but then you're in danger of missing out when an author shifts focus.
People who have time to read everything don't have that problem, I suppose, but unfortunately I don't have time to read everything.
PJ