I'm a K&K guy that has entered the James May Ultra Tonic camp. Did the Ultra Tonic conversion on a K&K equipped OM-21 & was immediately impressed! Better in every way.
http://jamesmayengineering.com
I'm having an old D-18's large rosewood bridgeplate removed & replaced with a small maple one &, while I'm at it, replacing the K&K that was installed with an Ultra Tonic V3. Yes, I'm a believer!
Frank