Perhaps some users with in-depth knowledge can add more content?
I think it’s pretty good, and I’m happy that we even have one (they tend to delete stuff they think isn’t notable enough; the first Hugo article was deleted).
I didn’t know that!
So, I wrote that first article, so it may not have had the most neutral author 
Also, Wikipedia doesn’t really follow their “notable” guidelines. I’ve seen Pages that passed their guidelines but were repeatedly deleted (and they put a nail on it, too because people kept submitting improved versions). And then there are Pages that doesn’t pass their “notable” guidelines, yet they refuse to delete. 
(Even the no “self-” rule isn’t really followed. It depends on who is reviewing, and the current head of category at the time.)
I checked the search results and the Hugo website pops up first. So, Wikipedia is not high up on the totem pole of selling Hugo to new users.
No, but having a Wikipedia article does wonders (I imagine) to your Google Page Rank, so just “being there” is very important.
Yes it does. I get no less than 600 visits a month from Wikipedia on one of my sites.