We all have our preferences. I have to say trying out each longarm at a quilt expo or something is the way to go.
As for a used machine they less pricey and a good way to start.
I own a Gammill, and have purchased my second one. if you live near WI At the Heart of Quilting would be a place to try these out. Beloit WI.
Best to try them out first. give me a pm if you live close to me. I'd be happy to show you my machine.
Enjoy