I personally use optifine because it smooths the game play, but that made me wonder what you guys think about performance enhancing mods. I don't think that it should be disallowed because its like banning powerful computers, however I've heard people argue against it for reasons like "it makes the playing field too complex." Just a discussion.

There shouldn't be any problems with Optifine, although just be careful with other ones. Any mods that would affect the actual time (speed hacks etc.) are disallowed