I am currently at emperor level (standard map size). I find loosing most of the time is more fun for me because it provides a goal, and when I reach it, its ever soo worth it. But in argument I think its really dependent on the size of the map, and the type of map - IMO. I have been over time trying to win on all skill levels, on all map sizes. So far I have only beaten deity on duel and tiny, which doesn't make me a deity player when I reach small or standard map size, because when I do play, I always get my arsh kicked. But eventually it will be doable, and perhaps only do-able with certain civs. So to truly gage what level you are - I think - you should gage it against map size, and how many players there are, and even perhaps what civ you are.