Tube preamp choice- Vac Ren Sig IIa or Einstein ?

Has anyone heard both of these tube preamps? The Einstein I am considering is a MK I.
You have a pleasant choice to contemplate. I've heard both and this will come down to a matter of taste and system synergy. Given the investment you are considering, I would strongly recommend an in home demo -- even if you have to pay for the privilege.

For what it is worth, I own the Einstein Light In Dark amp and am very happy with the product and the impeccable service from Lee Island Sound.

Good luck.
I have the Einstein The Tube Mark II and it is paired with an Einstein The Light in the Dark stereo amplifier. The preamp is particularly remarkable and the amp is excellent.
I've heard both and own the VAC - great support from VAC as well. Comes down to personal/system preference and I agree with Jazdoc about trying to demo each in your system.