TIppmann Boss here as well. Ditto what Pat H said, sew anything but light leather. Takes a while to learn to sew by holding the work in one hand and operating the machine with the other but it's not hard. I bought the two different guides, the roller guide and the flat bed, I think they were worth the money. I use the flatbed for wallets, guitar straps, etc it's a little easier to keep the stitches really straight along an edge of things like belts, straps etc. I actually like the flatbed better than the roller guide although it works well in some applications and has the added advantage of being able to swing it out of the way when necessary.
Ken
Forgot to say, that for light leather I use a standard sewing machine with a leather needle and that works on 2-3oz leather really well. MIne isn't one of the cast iron models but I don't do a lot of light leather and even then I'm not a production shop. I find the combination of the two to work for me.
Ken