I *highly* recommend the 630 (or 635-which is a special edition with a decorative face and a few different/extra embroidery designs). Like your 1230, it has a 5.5mm stitch width, so I think you'll find the sewing feel to be very similar. However, you should consider keeping the 1230 as a backup. It's soooo common to read someone lamenting that they sold or traded their older Bernina.
If you keep the 1230, you might try a 9mm machine like the 640 or 730. They offer wide decorative stitches, auto thread cutting, and low bobbin alerts. Some people (myself included) prefer the 5.5mm machines for narrow seams and hems, some find the 9mm machines work just fine for all their sewing. If you keep your 1230, it won't matter how that turns out for you
The new 7 series is coming out, and the 710 and 750 might be not much more than the Artistas. They have a new bobbin system and built-in dual feed (like IDT on Pfaffs). They are all 9mm stitch width machines.
I'd wait and try the 7 series and Artistas. If you find your 1230 sitting unused for a long time, you can always sell it later. Good luck!