I don't have that machine, but from what I read I think the float function is for free motion quilting, not the walking foot. My Husqvarna has this - instead of hopping, the free motion foot hovers just above the fabric. I really like it; my free motion quilting improved significantly when I started using this feature. If you've read how Leah Day modifies her free motion feet, her goal is to get it to work like this.
Personally, I will never buy a machine for quilting without this feature again - I like it that much. If you generally quilt with a walking foot instead of free motion, though, it won't be of any value to you.