I had a couple at our rail session the other night, I'd say in order to be totally in control... I was probably one or two over the limit of "just a slight buzz" what happened is I ended up videoing for a while and ppl kept handing me beers while I was standing on the ladder (good combo) haha
Anyways it didn't effect me horribly but my shit wasn't all there. A couple in the beginning made me relax because it was my first time riding rails since feb when I messed up my knee. This was at our backyard park though, I doubt I would do the same at a big mountain or even the local hill for that matter