A/C reports on frquency climbing to FL 200
ATCO "XYZ123 cleared FL300 and report to London on 123.34"
A/C "Climb FL300 and call 123.34, that was quick"
ATCO "always is..."
A/C "oh, poor girl, give her my number"
Or the new Eurocontrol ACAS II bulletin which talks about a conflict induced by a BAe 146 having good climb performance!!!