Hi Kate, I've been using the Butler for about 3 years on a MegaQuilter, and recently purchased the Juki QVP with Quilters Creative Touch 4 by Grace as a second machine. I've been quilting for clients for 8 years, started out FM and then added the Butler robotics. I quilt about 20 quilts per month. So far, much to my disappointment, I much prefer the Butler, and wish I had simply purchased another system like I had. Butler is far more straight forward, does it's job without imposing a lot of "software control" that I have found to be most frustrating with the Grace programs. Butler is not hard to master yet has the capability of doing very complex designs like irregular blocks, DWR's etc that I have found to be extremely difficult with the QCT4.
Good luck in your search!
Sandra G