I love my 7700 and am extremely happy with it. I only got mine, this year, so am still learning what it can do. So far, it sews beautifully, with any thread I've used (with no adjustments, from me). I love the needle threader, thread cutter, etc.
Only thing I wish it had, is better seam width markings (my eyes are getting older) but I have an idea how to fix that.