I love my Sweet 16 sitdown from Handiquilter! I spent some time on a long arm, and I found I just didn't like it as well. I really enjoy the feel of fabric under my hands, and I feel more intimate with my quilt when I use the sitdown. Besides, it also takes up a lot less room and costs less! I got mine in May, and I've quilted (I think!) 5 quilts, a bunch of table runners, and a bunch of placemats on it. Wish I had more tops ready, or I'd quilt even more. This is in addition to the practice sandwiches and the practice work I did for one quilting class.
For an earlier poster, the Sweet 16 is just like your domestic machine except on steroids! All it does it straight stitch free motion quilting - no stitch regulator, no stitch length, no feed dogs. You are the driver all the way. It has a 16" throat space and the table that comes with it has the machine facing straight at you, 90 degrees different than most people work with a domestic machine.
Most people have an initial problem with regulating tensions. Like most professional machines, it has a much wider tension selection than your home machine, and you need to spin the tension dial a full turn to make even small corrections. However, once you figure that out it will take about any thread that you can throw at it. I've used Aurifil (my favorite) in 40 and 50 weight, So Fine, King Tut, Yenmet metallic, Guttermann, YLI, and even the Superior water soluble thread (for basting).
Can you tell I really like my machine <huge grin>?
Pam