So you have trouble with free motion quilting? I was hoping with the accufeed it was going to be helpful for that. But, come to think of it, I guess that is a whole different ball of wax.
Don't fret about FMQing with the 6600!!
..... until I had my 6600, I thought FMQing was absolutely impossible.
THE 6600 is what got me hooked on FMQing.
FYI the Accufeed is not for your FMQing. However, the Accufeed is a great asset when doing straight/line quilting.
For FMQing, there is a special set of feet and a blue dot bobbin case that you can buy that really help make a difference.
Like many have already said ... the 6600 is a true workhorse and I can't say enough good about this machine. Hopefully, before long you will be saying many of the same positive comments about your new machine.