the main difference is the boss' have the canted floorbed. this means instead of riding on a flat baseplate like 99.9% of most bindings, you can angle the footbed to your liking which will make for a more "comfortable" ride.
I will offer my 390's for 100 shipped, I think it's a pretty fair price considering the colorway I have is somewhat rare, and the only place that has them is charging 140. your decision though!
I really think you will be happy with any rome binding, they make a solid product and customer service is awesome. They will send you whatever you need - no questions asked.