I bought a 2006 used Gammill Classic Plus 5 yrs ago and love it. I especially like the sturdy frame and ease with which I can do so much of the maintenance. Their tech support has been very good. It is a heavy machine,but I can run it with one finger too. And older Gammill's are oil hogs--but since it lays down so many stitches so quickly I think that can be expected.
I agree with others that it would be worth your time to go to a large show and try out different machines--they all have their own "feel". I also highly recommend one that is designed for industrial use (Gammill, Innova, Nolting) especially if you plan to quilt for others.