The EI 12AX7 gold used to be my favorite current production preamp tube. They were wildly inconsistent though, but were great if you got a good one. The Tung Sol Reissue 12AX7's are my current favorite current production preamp tube...
I got 2 from Dave as well. It really does rock. Made the amp a little more aggressive. Switched out 2 Mullards and put a Telefuken in V1 and the Ei in V2. Good combo for the SLO. The Ei is effecting the OD channel but not the Clean which works perfectly for me.