I use McCormack DNA .5's with the Vandersteen 2CE Signatures in a vertical biamp. I would definitely recommend the signatures over the 2CE. I have used three preamps, the Audible Illusions 3A, L-1 linestage and the McCormack TLC-1 passive with the McCormack upgrades(TKD volume control, etc.) Any of the three are superb choices. I favored the L-1 linestage a touch over the 3A and am currently using the modified TLC(which I personally thought sounded best overall)The 3A had a little to much of a good thing and it was relatively noisy(background hiss)The L-1 also has some hiss but not as bad as the 3A. Both are a touch dark. I've noticed this on other speakers and systems as well. The TLC is dead quiet and a touch more open than the AL's. I'm using a Meredian 508-24 as my only source. It works incredibly well with a passive preamp.
I tried the McCormack DNA125 and did not think it offered anything over the .5 if as good. Seemed to have a little roughness which I attribute to the input blocking capacitors that the .5 does not have. The DC offset was removed from the 125 which is why it has the blocking caps.
All of this is using the Vandersteen's. The synergy may change with other brands of speakers. For the record, I'm using Tara Labs Master Gen. II for all speaker cables. It has a slight(very)midrange leaness which really compliments the Vandersteen's and opens up the sound stage and presents a really realistic image and focus(one of the best I've heard in 35 years of messing with this stuff.) I honestly never thought the Vandersteen's could sound this good. Of course, this has been a years worth of experimentation on this system alone and drawing from all the other components I've tried with the subsequent wasted monies! One last note, Steve McCormack is right on using the Cardas speaker jacks. Unbelievable improvement over the original plastic jobs. He also right on about WBT input RCA's. Sometimes things can be simple.