Hi
I have the Memorycraft 6500 Q machine and I love it. I've had it about 18 months. I don't know how similar it is to the P edition tho. Mine came with a box containing about 10-12 different feet.
I don't have a ruler foot tho, so can't comment on that, but all the other features are good, I don't think I can find one aspect of the machine that I don't like. (Except my automatic threader doesn't work , but I know how that came to be - don't let a 12 yo accidentally touch the foot-pedal whilst threading lol.)
I've even been known to go into the room just to give the machine a pet in the passing, when I haven't had time to actually use if for a few days lol.
I'd be interested in finding out a bit more about the ruler foot you mentioned tho......
Cheers, K