I have owned the 6600, 7700, and now the 8900. The big advantages I see in the 8900 are the snap off needle plate and snap on feet for acufeed (STD, 1/4 inch, open). These are a big deal for me. I frequently change the plate from single hole to wide, I change out my bobbin case when I FMQ, I take advantage of the 1/4 foot because I like how the feed dogs hit the edge. I like the "one touch" button settings.