If you don't really need it, then why get it?
I just got a MC6600 in the fall ... the dealer still had new MC6500s available, which is what I first started looking at.
Once I looked at the specs, it was an easy decision to skip the 6500 and go for the 6600 because of the features that I would not have got in the 6500.
Go to Janome's site and you can easily see the specs for all their models and decide whether it suits your needs or not.