I believe Hughes use a Saenz bench which seem to have a reputation for better #s than other brands. I've used a Super Flo 1020 and had a lot of work done on a SF 600 and can tell you that those two benches don't jive with one another. Then there are all the do it yourself home build benches out there ???
The bottom line is that a flow bench is an A-B test tool. As much as we want compare #s from one to another these devices are more like home made yard sticks not micrometers.