Well, since Santa got me a fabulous treadmill instead of a Bernina with BSR, I have decided to buy a used Bernina Artista 170 from an online dealer, and use that machine for piecing. It has the 5.5 mm feed dogs and CB hook that work so well for piecing. I also like the notches in the side of the Bernina 1/4" foot, which allow you to SEE the fabric and be sure, without going blind from eyestrain, that the fabric is lining up with the foot edge.
Then I will save up, not for a Bernina with BSR, but a full sized frame with a stitch regulator. Both Hinterberg and HandiQuilter setups have been recommended, and I hope to demo them at the big Quilt Expo this spring in Puyallup, WA.
Just as an aside, I did talk with our local Bernina store a few times (to make sure Santa had the right thing on my list!!!) and they really missed the boat with me. The first salesperson was nice, and enthusiastic, but directed me away from the 630 (feeling I did not need the embroidery unit, which was true, but she never considered a quote for just the machine, either), which in the end I vastly preferred for the better lighting and larger and colour computer screen. I would have bought the 440 with BSR that day IF they had allowed me to trade up penalty free if I found I preferred the 820 in 6 months when it comes out. They would not, so I started looking into used machines online (there are none locally). Incidentally, if they had offered to prepare an information package for me that I could attach to my Christmas list, with info and contact info for my husband, he would very likely have bought me the Bernina! I went back just before Christmas as a dealer in Toronto (where my dad was pricing machines for my mother) said Bernina had just emailed out a sale three weeks before Christmas, which included a great price on the 630 without the embroidery unit but with the BSR (just what I wanted). The local shop offered to "match" the price (but wasn't this a national sale originating from Bernina Canada???) but "Just For Today". I really hate hearing "Just For Today". I find it high pressure and demeaning, and can't help but feel taking that price will make me a second class customer from then on, which is silly as I would be paying just as much for accessories, etc., but there you go. I left the shop with a bad taste in my mouth and decided to pass on the new Berninas entirely, get an affordable used one for piecing, and put my money into a frame setup with a stitch regulator instead.