I have one but am not impressed. The grippy gloves and slider make all the difference in the world, spend your money on those instead!

Leah Day has an awesome blog where she talks about quilting on a DSM and she has a ton of designs, with videos, that she shares on her blog for free. http://freemotionquilting.blogspot.com/

She also talks about what works and what doesn't with doing FMQ on a DSM.

I have one and I don't care for it. I have better luck with my Machingers Gloves...