It is to each their own views of these two machines. Personally you won't go wrong purchasing either one. I settled on the 6600P, as it offered everything I wanted and needed...I didn't feel that I would utilize the 7700, my 6600p came with a table also. Does either of the machines you are looking at come with the table? It was a nice perk for me. But really go to Janome site and do a comparison.
http://content.janome.com/index.cfm/...ewing-Quilting
Both machines are here...
Best of luck on your future purchase.