I have wanted to try Khao San for a while (a while being a year). I've even gone there two or three times, each time getting scared away by the massive line-up out the door because this place doesn't take reservations. Toronto weather in the middle of February + huge line-up = does not comprehend why everyone is lined up in the snow. But finally, finally, despite still waiting in line for half an hour to be seated, I tried it. And it was good. Just not good enough to justify the wait.
The place is packed, and loud. We got a seat at the bar (which is fine) but I kept getting jostled from the back by a lady who didn't know to keep her elbows to herself. Service was hit and miss, since there's so many people that the servers kept saying that "they'll get back to us" because they were in the middle of something. The food was admittedly quite good, and their portions were filling.
Did I enjoy my experience? It was alright. Would I go back? Probably not. If you're not a fan of really loud, cramped spaces, then Khao San Road is definitely not the place for you.