I just installed mine to replace a REF 75, it is a noticeable upgrade in almost every regard right out of the box (I do miss the meters though). I will report again once I have more hours on the unit.
New Audio Research Reference 150 SE
I just heard from my AR dealer that a new Reference 150 SE that uses KT150s will start shipping out in early March. Did I miss this on another forum or is this new news? This might explain why they have not endorsed using the KT 150s in the current Reference lineup.