Avinor in Norway use RELTA, and so far no one has flunked it.
(I got a 6
,and I'm glad it't not a written test as well, because my spelling is, well, poor!
)
The Swedes let their controllers use private test if they pay for it. Some have used a test performed by the Swedish glider pilot asociation for their members. They have a 100% level 6 success rate.......
Given the level of English spoken by Swedish glider pilots in general i find that highly suspect. (They use Swedish on the R/T 100% of the time IMHO)