hi ... our small production shop for 2nd ops had a J bridgeport and a couple small Clausing 8250? drill-mill machines .
we added the sheldon when we got a chance mostly because it is a very nice piece, and couldn't pass it up from another closing shop.
we never used the sheldon very much, and mostly for 2nd op ... the rusnok is a very nice quality add-on and fine for LIGHT DUTY 3/8 end mills ... it would be a compact killer unit for a hobby shop, having both the horizontal overarm for slitting and a collet drill-mill for vertical. this one has a power drive on the slide. it is on a steel cabinet about 4 feet on a side, the unit is about 6 feet tall.
on the downside is that the rusnok uses it's own special collets, and the rusnok is not for hogging out rough shapes like a bridgeport, just final cuts. if you have a contract to make parts, i would go bridgeport ... if you want to fiddle in your workshop, this is a sweet piece.
hope this helps, ken.