I don't know what all those machines have to offer, but I'd make sure the frame has a deadbar and is not the type that you have to adjust the back rail every time you advance the quilt. My first frame was like that and it was such a pain.
And make sure the rails of the frame are very sturdy. My first frame had rails not as stiff and after a few years of use they started to bow in the middle and that gave me greif too.
I finally upgraded to a Handiquilter (fusion) and it took quite a while to work through the operator error issues, but now I feel I've got it dialed in and really like it. I like that Handi Quilter is always working on upgrading the robotics program and adding features. I started out without robotics and added it later.