I own a M54 Rotatrim. I would not recommend buying it for any purpose, let alone cutting canvas.
I'm working with the rotatrim for almost a year now, and rarely use it. It cuts thick paper fine, but really chokes when cutting canvas. Since it doesn't come with instructions, I don't know if it is supposed to work with canvas, but my guess it isn't. the head "jumps" out of the track, because the tubes has elasticity, and you can't relay on it for cutting canvas. it is not meant for foam boards at all.
I would also like to hear if someone uses Logan product. It looks great and the price is good. I've seen the products of Keencut at work, and they seem quite impressive. their price is somewhat high, though.