I have the slightly larger cousin.
I have not really used it much. Should do more with it. I did take it apart clean debur and lubricate. These are typical of the import machine a solid machine but fit and finish need help. also in my experience you need to put a radius on the bending leaves. A sharp edge will put grooves in the metal that are stress points and cause cracking . I was trained in aircraft sheet metal. a small radius is ok but never a sharp bend . IIRC the edges on the leaves are shipped pretty sharp and with burs.
just a couple of observations, both machines rated at 22ga steel so a bit thicker with copper.
the 7 1/2 inch machine is 27 lbs and cost almost $200
the 12" is 114 lbs for 260$ plus you get the slip roller
I picked mine up at the Grizzly show room a few years back, when it was on sale, so saved on shipping . IIRC looking at the two side by side I felt that the 12" 3 in one was a better value .
I have heard that the 30" units have a bit too much flex.
Hope this helps.