Keep your 630. It's a killer machine, and can do anything the rest of them can do.
I did a comparison of embroidery on the 630 and the 830 last year.
http://www.createdbycj.com/tinkle-ti...-part-one.html
While the 630 doesn't have all the bells and whistles of the 830, it does stunning embroidery, and is just hands down an awesome machine.
You can do borders! I know rehooping is a bit of a hassle, but most things like that are, even with the machines that make it more simple.