I've driven stock vs. weapon R intake's on 4th gen h23's before.
There definately is a noticeable difference from stock, as ****ty as I heard the weapon-r's are.
The cars I drove that didn't have the performance intake seemed to drive a lot tighter, i definatly feel a bit less response on the throttle but once it gets going the growl and extra power in the higher end is awesome .. I didn't drive a great array of cars but.. I hate opening my hood to show people and seeing that weapon-r sticker ..and i dont want ot take it off so its half on .. blech ..
guess I will have to try and be the AEM guinea pig

.. does the H23 CAI also fit the H22 ? I have future plans on doing a swap
Great writeup on building the head of the H22 in honda tuning magazine. It's all skunk2 **** but .. a good read IMO.