I have a Bernina 730 that has a BSR however, I have been using Leah Day's free motion method and find it works better for me than the BSR. I think you should try it out at the shop to see how you like it. Also, try Leah's method with the glide sheet. You can get different specs on Bernina machines at
http://www.berninausa.com/product_overview-n2-sUS.html. Good luck - you will love which ever one you get.