Hi, Jan!
Although I can't comment on the 2 machines that you are looking at, I will share a little experience with the BSR.
I have a 730 that both my daughter (who is 14) and I use. I thought that the BSR would be a big help to me as I was learning to machine quilt. Surprisingly, I found the my movement of the quilt sandwich was not a steady enough motion to have the BSR function well. I got quite frustrated with it and have been doing free motion quilting on my most recent 2 quilts. Working on the free motion technique, I am finding that I am more comfortable "driving" with the foot pedal.
My daughter on the other hand, jumped into machine quilting a full year ahead of me and has only used the BSR. She has done her quilting on a few quilts with the BSR and really loves using it. (she also doesn't drive a car yet, so she isn't used to using a foot pedal for anything).
So, I just thought I would mention that we are both relatively new machine quilters and one loves the BSR (my daughter) and one (me) has found that I do better quilting without the BSR. Ultimately, I am glad that I have a machine with the BSR, as it did help both my daughter and I take "the quilting plunge" with a little more confidence!
Have fun figuring out what you want in your next machine! I always think that the journey is half the fun of getting to the destination!
Mary Kay