I went with the K&N RU-2750. It is a slightly larger filter, does not have the chrome tops, and does not have the offset built into the flange. And it fits with the British Customs Air Box Elimination Kit.
Basic math will tell you whether one K&N outflows the other - assuming basic shape is the same (i.e. Larger is better). On the other hand, if your motor only pulls 200cfm and your air filter supports 300cfm does it really make a difference?
