It's the closest thing to a 201K2, with the gear driven motor. It's all metal, no belts or pulleys driving the mechanism. It's suppose to be easier to set up for free motion stitching compared to a 201, because of the bobbin case. Both are drop-in class 66, but not exactly the same. I think it has a stronger motor than the 201s too. Model 15 is a favorite with quilters, and I guess there's not much advatage in that respect. It's a slantomatic, and it was made to have better overview of the stitching and needle movenets, and they have their own line of buttonholers and accessories. It might have some userfriendly advantages; another is it's cast aluminium, weigh less than the older cast iron machines, but still sturdy enough.