I have both a US tubes and a ROOR and the tubes is superior.
Thick straight and true. I have had friends drop them on tile and hard wood with no real damage done. Plus Roor has all kinds of problems with counterfeits and are not being sold at any respectable glass shop in town anymore.
Roor starts at what 3.2mm US tubes I don't think goes below 7. They also add glass to the beaker for when it balloons out.
Roors may do work but they are a thing of the past.
editt-
One look at the female joint on the bong and you will agree that the tubes is superior, when I mean 7mm I mean 7mm even up to the downstem.