We are assuming you mean the K&N filter, or similar style.
They can work fine, and as RB Hoge says, it is best used in combination with a free flow exhaust system, and a re-jetted carb.
Sometimes these short pod filters can introduce a little bit of a "hiccup" in the throttle response at small throttle openings, but other times they don't cause that, and work fine.
The main issue with these pod filters is that they don't have any support, and it causes the entire carb and filter to hang unsupported by the rubber manifold hose. This usually results in a failure of that rubber manifold hose in a fairly short period of time. Making a support bracket for the filter will help.