I bought me a Boss several months ago. I have a leather shop and make a lot of gun holsters, wrist cuffs, motorcycle stuff and the like. I use 6-7oz leather for most everything, some 4-5 for a few things. I use my Boss every day .. and it is turning out to be a piece of crap! I have had the arm gear replaced twice and just ordered another. The teeth keep breaking off. Today the gear that drives the bobbin broke on the uptick! Around Christmas .. by busiest month I had to send the entire machine in because a gear broke and to put all the little springs back in after the gear replacement is nearly impossible. Yesterday the bolt that holds the stitching handle on sheared off. Thats the second time that has happened. Tippman says they know about the problem but have no plans to re-engineer it at this time. I drove a pin through the top of the handle into the shaft .. see how that works.
Tippman is very friendly to work with. Great customer service. The gears in this machine however are made with cheap pot metal. This is a machine that is only for light very occasional use.