I just happened upon this and will throw in my 2 cents. I've had a 730 for about 4 years now and really love it. The good - in my lifetime I will never be able to take advantage of everything fully. I've never had a problem with it other than the fact that my bobbin sensor doesn't always tell the truth. I'll mention it again when it goes in shortly. It also comes with the BSR for free-motion (not sure if one or both of the other models you mentioned come with it). I've gotten very fond of that attachment.
You need to consider the 5 mm or 9 mm facets as well, I don't mind the 9mm and use a single stitch plate for straight sewing with no problem. I am an all-around user from garments, upholstery and home dec, quilting a bit more these days. It seems to work well for me.
Good luck, Deirdre