That extra $1000 could be used on a lot of fabric and you'd still have a great machine if you went for the 7700. That's what I keep telling myself because I have my sights set on the 7700 but know how easy it is to just keep wanting more.
You know yourself. Are you easily contented for a good, long while with something significantly upgraded from what you now have, or would you be wishing in a year that you had gone ahead and splurged? I'm curious to follow this thread because I have neither machine, just a little Janome DC 1050 that was a huge upgrade from my mechanical Kenmore. That being said, I'm going to hem jeans this week and I always pull out the Kenmore for that. If I had a 7700 (which I've test driven with 6 layers of denim at the quilt shop) I would use it, no question.