What are the differences between the two? Just bought a used 3D Array and now I feel like I should've waited...

Presumably used=less expensive, so you're good.

Minor revision, not to worry. Here's an excerpt from the September 2014 announcement to GoldenEar dealers regarding the improved version:

We are also pleased to announce that we are now shipping an updated 3D Array, the 3D Array X, which has been updated to incorporate our new Mag-X Coupling™ Crossover Technology, for improved interaural crosstalk cancellation performance even beyond that already achieved by this award winning and best selling passive soundbar. The U.S. retail price on the 3D Array X remains $999.99/ea.

Ok. I don't have time right now to check it out in person (actually, I don't like the sales person here in the Atlanta dealership; he's not an audiophile, just a sales guy); so can you tell me if it just improves on the crosstalk or does it image better?

Imaging is related to crosstalk cancellation in this product, so presumably yes, although I have not auditioned the two side by side. The engineers felt it was "better".