Upgrade from Vandy 2CE sigs to the sigs 2 or 3a

If you're going to bother to upgrade go to the 3. It is a
significant upgrad in scale and bass performance. Going between the 2s is more of an incremental move.

If you like the Vandy sound why stop at the 3's. The Quatro, or 5A's are really much better still. One of the joys of owning Vandersteens is that they are upgradable...you will always have the cutting edge.

With the 3A sig you get the 5's tweeter and extended bass as Narrod stated. Later if you wish you can get a pair of 2Wq's and will have the equal (?) of the cloth Quatro. I have the 3A sig's and the 2Wq's (pair) 80-85 % of the 5's (?), for sound, money and the ability to add to the system the 3A sig's are a great buy, and they are very good by themselves if you can't add sub's.

I owned the Vandersteen 2CE Sig II's for a month or so. I was forced to sell them due to grandkids and pressure from my wife to cut down on the hobby some and build a play room where my second system was.
I have owned the 2CE's, 2CE Sigs, 2CE Sig II, 3A Sigs and the Quatro's.
The sound of the definitely unbroken in pair of Sig. II's is a definite departure from the 2CE Sigs. IMO, they are cleaner with a bigger sweet spot. For a Vandersteen, they almost sound lean! The bass is quicker and the mids more defined. However, they have lost some of the warmth of the other Vandersteen's. There is a big enough departure that I would not call the difference "Incremental." My pair were a "30th anniversary edition." What that means, I don't know.
Compared to my last pair of 3A Sigs, the mids and highs are close but the bottom of the 3's is more robust as they should be. The 3's also sounded "Bigger." Vandersteen has done upgrades to the 3A Sigs and I was told they don't sound the same as my older pair now. I can't speak to that.
The Quatro's (non wood)are the better of the ones mentioned above but sound more in line with the 2CE II's. The mids are better defined and the treble sounds more extended and open.
The bass is a good bit better (all the adjustments help here.)
I would find a dealer and listen to the 2CE Sig.II's before I made a decision. They are a big enough departure to warrant that.