I tried out the demo model at the Essex/Baltimore Tandy a couple of weeks ago. It's a nice machine, it was powerful enough to chew through 2 pieces of 5oz veg tan, although that's probably extreme for it. Really nice speed control. Just wish it could take a bit heavier thread sizes.
I just checked out the Sailrite web page-the Tandy Stitch Master looks like a beige colored version of the Sailrite Ultrafeed LS1 portable that's been installed into a nice little table with their workhorse servo motor. I like the smaller Tandy table, but for close to the same price, the Sailrite Fabricator sounds like a better deal with more capability. The site says it will take up to V-138 thread.