I had one. I only used it once, and that was for a huge quilt, so perhaps I shouldn't complain. I have seen John Flynn using one for small quilts at shows, and he makes it dance and sing. But I don't see why you would need one for small quilts... I bought the long rails and found that they were so heavy I couldn't really manipulate the frame to quilt. Using the long rails also requires that you be able to move the rail in both directions its full length, so your room needs to be about twice as long as the rails. So it can use a lot of space while you're using it, but when you put it away (and you will probably find that it is "put away" most of the time) it won't use much space. I also had a hard time loading the large quilt on the rails, trying to get it on straight and tight. Once I got it on, I couldn't manipulate the rails to make a design, so I wound up using water soluble thread to baste the quilt in straight lines, and then I quilted it on my DSM. And now I have a longarm.
I think it was the attempt with the Flynn frame that tipped the scales on whether to buy the longarm or not.