I tried the BSR and didn't like it at all - slow and 'draggy' and took it off. My FMQ is far from perfect and as the other posters have said, you will still need to practice.
However, that said, the FMQ I did without the BSR was lovely and smooth and produced a nice stitch, albeit not necessarily all the same length, lol.
For me, I can't justify the extra expense for something I wouldn't use a lot, when my existing machine has most of the Bernina features.