Yes, myself, Heliona, Wilko and Aravar went last year. It was quite a nice afternoon out... reeeaaally good beers with names like 'Ent Draught' and 'Completely Legolas'.
Other good stuff were falconry and a dog show, which were pretty good. There were also some fairly pleasant bands on during the afternoon. Nothing special, but nice.
On the downside, the event is held in what feels like a school hall. The only 'decoration' or 'theme' beyond the bar itself is a bit of straw on the floor. It was a rainy day when we were there and my idea of fun doesn't usually include sitting in an atmosphere-less hall on uncomfortable chairs that you can't leave unmanned for fear of losing them to someone else sheltering from the rain. The food on offer was pretty basic, Pie & Peas... quite cheap, not bad but nothing interesting.
The best thing really is that you pay a £2 deposit for your beer glass and the glass is awesome. I think Heliona has a picture somewhere. None of us claimed our deposits back!
So, on the whole: I would go again if only for the beer (although unfortunately I can't make it this year, I don't think), but I wish they would do more with the theme of the day beyond the names of the beers.