whats wrong with the emgo filters
you mean other than they are cheaply made garbage?
Lets start with the obvious, the metal mesh filter is good for bugs and stones and such but really doen't filter particulate matter out, like dust, or pollen. Honestly they work about as good as a fine mesh screen on a set of v-stacks.
ever look inside an stock honda airbox? the rubbers that mount to the carb are actually mini velocity stacks. Without getting into the science of velocity stacks, they are that way to help the bike run smoother at idle and throughout the rev range. Real K&Ns have a similar internal "velocity stack". The emgo is just a flate piece with a hole cut in it. Every wonder why pods have a rep of being hard to tune "just right", this is where it comes from.
on top of that the chrome is cheap and rusts easily.
For looks alone with complete disreguard for how your bike runs, they are cheap and kinda good looking which makes them popular. In this case you barely get what you pay for.
to me personally...emgos on a bike pretty much tell me you have no idea what you are doing when it comes to motorcycles and how they work.