Bernina, as far as I know, actually has a pretty good patent on it. I know that other companies have come up with other techniques (Husqvarna has or had a system that was like a tray you'd put over your machine that would hook into a sensor, but using it I found it awkward at best and utterly unusable at worst, and you could only go so far without having to move your quilt with some serious difficulty.)
What you might look into doing is taking a class on using a store's longarm. More and more often, you can take a $200ish class, and then rent out their longarm for a reasonable rate. That at least will give you the opportunity to find out how much you really like it.
The BSR is ... okay... for what it does (it has a lot of problems with red fabrics and plain fabrics), but it's far from perfect.