Honestly, the only way I'm in favor of antes is if there is three or more tables of players.
That actually talks me into it ;-)
Over the last 2 years we've been about 15-25 per tournament, and since I have max 8 players per table we quite often have 3 tables.
This is the blog post that made me want to use antes:http://danielnegreanu.com/antes-in-tournaments/
The symptoms Daniel describes of a tournament without antes fit quite well with how my tournaments are played. I can't have longer blind levels than I currently use due to time restrictions, but hopefully antes can change the dynamics of the game.