Is there a huge diff, between 2CE Sig II & 3A Sig?

As far as any audio expenditure goes, yes. You'll get a much fuller sound, more impact.

If you have a choice, which would you get, a 6 years old 3A Sig. or a 2 years old 2CE Sig II?

The 2CE signature is one of the best speakers when it comes to performance per dollar. It might get you around 80 to 85% of audio nirvana. The 3A sigs are superb but might get you an extra 5 to 10% of the elusive audio nirvana.

If it worth the extra money for the smaller increase in performance then go for it!

I would call Vandersteen regarding the used 3A question.

Well, as I have learned recently, I've asked Richard Vandersteen if they made any changes on the 2CE Sig II since they started the production, and he said "absolutely" but didn't change the model name and this goes the same for for the 3A Sig. So, what he was saying is that the older 2CE Sig II is not the same as the 2CE Sig II NOW. I just thought I share this info with you.

Still hard to say the 2ce I was running quicksilver v4 on with kimber cable and a asethix pre amp and every change I made to the system herd the speakers where very transparent. As I said the 2wq made a big difference. The 3 will be a bit cleaner I think it is the sweet spot in the line.

Anyhow he is alwas improving little things. That does not mean an old set is bad. If it was a huge improvement it would dictate a model name change.