I don't have either machine but, from years of trying out machines at quilt shows and also following Yahoo groups, I am pre-sold on the Innova. Innova is my "dream machine". If you join the two Innova groups and ask, I think you will find quilters who have used other systems (including Gammill) who will compare (and the Innova always seems to come out way ahead). Here are links to the two Innova Yahoo groups:
https://groups.yahoo.com/neo/groups/innovalongarm/info
https://groups.yahoo.com/neo/groups/innova_longarm/info
(One group is owned and moderated by Innova; the other is owned simply by users. Never can remember which is which. Lots of people post on both groups.)
Do you really need robotics? My suggestion would be to get the Innova with lightning stitch, work on your free-motion skills, and add robotics later only if you think it will really be useful to you. The only reason I would get robotics is (1) if I were quilting as a business, or (2) had a physical disability that prevented me from working at the frame for a couple of hours at a time.