Well I'm sufficiently crusty and wimpish and British to think the Red Lion is GREAT!
I was brought up to believe that if there were flies in the vinegar one should pretend not to notice and swallow them down, to avoid giving offence, or if you were feeling particularly aggrieved to mention it to the waiter but start off in true British fashion by apologising for mentioning it. Certainly not make a big fuss - blimey, we're not Americans are we?

I have to say, I've never seen a fly in the vinegar though, and think the food is excellent.

As for the pub itself, it's a huge asset. If you judge things purely in terms of the human pleasure it provides it couldn't be placed more perfectly, and the tables in front are just what's needed. It must add to the Avebury experience for tens of thousands of people a year. Imagine what a sad how d'you do the village would be without it.