I just got myself a new machine. I can tell you some of the things that were important to me. One of the greatest things on this machine is the LED lighting! The throat area is big, so I can do machine quilting on it, and there are lights above the throat area! I want the presser foot to "hover" when I'm chain piecing or doing machine applique. The thread cutter under the needle plate is pretty great. And the "Jumbo Bobbin," is amazing! It holds 70 to 80 percent more thread than a regular bobbin. Service where you buy the machine is important. Where I bought mine, they give 3 years of free service, plus classes if I want them. And the owner of the store services the machines, at the store. He doesn't send them out to somewhere else. I wanted the blanket stitch for applique and the asterisk stitch ***** for hemstitching. I have total control of the presser foot tension--which I didn't have on my last machine. I have a knee lever to lift the presser foot hands-free. I have 11 needle positions. 5 built-in alphabet fonts. A stitch regulator for machine quilting. Tons of decorative and utility stitches. I got the 9mm needle plate hole, so the decorative stitches and alphabets have more detail than with the regular 5.5mm needle plate. It has the "dual feed," which is a mini walking foot that drops down behind the presser foot. It's great when I'm piecing. But I can also use my awesome walking foot, too.
I got the Bernina 590 with embroidery module about 3 weeks ago, but haven't had time to use the embroidery module yet. I couldn't be happier! I'm really enjoying it!
Good luck in your search!