McCormack SMC Audio Upgrades

I am considering purchasing an older DNA 0.5 or DNA 1 and having it upgraded by Steve McCormack. Is there anyone out there that has had experience with the upgrades and would like to share their thoughts? I am particularly interested in the sonic differences between Rev A and Rev B. I would also like to know if anyone has upgraded their TLC and the effect that it has had. Thanks in advance for the wisdom.