I still have my 7700. Traded in my 6600 (which I hated with a passion). I've had it since it came out. There was an issue with the 1/4" foot, but then they came out with a new one and it's fine, it's my go to machine. I also had the 11000SE and traded that for the 15000, wish I hadn't though, it's a little above me and I only used the 11000SE for embroidery, should have kept it.
Good luck with your search, but if you want a larger harp don't get the 6600.