I've had the x12 and still have scm-11s. I don't know when the revised ATCs will actually be available, but if it is soon, I'd wait to see what the revision does for them.
That Vincent has some sock and shouldn't have trouble driving any of them and the tube bias to your system I would think would keep them from sounding analytical.
I really think you need to listen to them somewhere if possible. If not possible, buy the x12s used and compare them to the ATCs you can hear locally. If they aren't better to you than the ATCs, you can sell them on and buy the ATCs locally.
They are close enough, IMO, that a demo is a must. For example, for me, both the 11s and the x12s were more similar to each other in than either is to my current Harbeth P3, so I'm at a loss how to describe them in a way that would help you apply my results to your situation.