This topic of speed restrictions appears to have devoloped into a look at R/T standards, which I think is worth comparing around the world. Speaking as a "Brit" I like the way our American friend group numbers together, I find it easier to remember, readback and takes a little less valuable airtime. Also there are so many stepped on transmissions nowadays that equipment like "Contran" that stops you doing so should be invested in by the airlines and ATC.