Not a JAR thing, I'm on the wrong side of the world for that!
Just that all the other methods require you to get off track to be able to stay on track, which doesn't sound that smart or efficient to me. And we don't have radar control in this part of NZ either, so ETAs and therefore proper nav logs are still a necessity. If you're going to get the groundspeed you might as well read off the drift while you're on the flight computer...(One day I'll be able to look back and say "when NDBs were still around" ...)
Anyway, doing it all on the ground beforehand was good enough to get the renewal signed off today. And with 20 knots on the ground and I don't know how much at 3000' I think it was well worth it.
Woohoo!
------------------
Confident, cocky, lazy, dead.