I have the GO and love it, you can watch the different places i.e. Nancy's Notions, and other places that sell Quilting merchandise and find sales. I think when you purchase whichever cutter you naturally are going to love it because that's why you chose it.
I'm 72 with arthritis and can turn the handle on the GO, whereas I have trouble with the rotary cutter. Maybe it's just an individual preference.