Changeover to the new model has been going on all year, Tom had some X3's on hand long after SCT stopped shipping them so it was a choice if you wanted the new "upgraded" version for quite a while. Lots of discussion on whether the new features were "worth it", old stock lasted almost to the end of the year.
Don't know when he ran out exactly, it was quite recently. IIRC he had some used older units as well he advertised here. Contacting him directly is the easiest way to get things straight when ordering so you know exactly what's going on.