I sm new to this sewing world. I have a Singer 4452 which is supposedly a heavy duty machine. I does have a metal frame and it has pretty much done what I've needed it to do. Now I have been looking at a lot of you tube videos on sewing masks, leather, DIY tactical and camping items. Sailrite seems to be a very popular machine with people who sew leather, heavy canvas items, bags, pouches, etc. They are a specialty company who seem to work a lot with sail makers. I think if you were to go to you tube and search for Sailrite, you will find a number of videos about these machines. Again, as being a newbie (and former mechanic, current biker dude who does his own maintenance) I am skeptical of a lot of things and often do a lot of research. I personally, if I could afford and "really" had a use for one, would consider a Sailrite. I believe they are a good machine. But then I'm new here, and would not blame you for not trusting my statements!!