I have a 15-91 in a cabinet that my husband bought for me. It's a nice machine. Mine is from 1945 (has an AG serial number) so this one is probably a bit newer (AH serial number). Having the tensioner towards the back of the machine makes it easier to see where/what you are sewing. It has a "screw" underneath the machine that you turn to drop the feed dogs for free motion quilting and it is gear driven so no belt to worry about and therefore is a bit of a stronger sewer also. A lot of these machines need rewiring due to deterioration of the wires so check that out if you go see it. Still, you can buy the wiring online at sew-classic.com. As I said, I like my 15-91 ... a lot! (Funny how the ad is listed at $95 then in the write up says something only $100 with tax cash. What the heck does that mean?)