I prefer 1/8th of the BB but notice the WSOP was 1/6th and the EPT was 1/10th so it all varies. I think a good running ante is essential in any structure to smooth out the average stack throughout the tournament, I always think structures without antes are fatally flawed as they create an elastic band effect where when the middle stages of a tournament is reached the average chips in the tournament will be short stacked, antes (mostly) prevent this from happening, realising a smooth flow of eliminations rather as mass eliminations at key stages of the tournament and crapshoot (or bingo) poker occuring, which equates to more work for us!
The majority of players will never find out about these structure problems where there is no ante unless they are running deep in the tournament as the rest will overtighten and then be forced to move in with marginal holdings.
As Chet says I don't think it is essential what level you play your antes at but I do think having them is essential to any good structure, but I do think the higher the ante runs at the better and smoother the tournament is, favouring the better players.
Regards
Stuart