but I still don't understand...
why should different airlines have different sizes / weight specificications for their o/h ?
I can understand it could be because of different a/c but even then ?
Ok even if you were to give me that piece i'd take it as long as on my ticket you specified ( since you know what's the equipment you're flying and I don't) the dimensions and weight ( esp for international) .
Also remember on intl flights, duty free could add up to another 5kgs per pax, which could be another 1 tonne per 200 pax which is nowhere on the trim sheet....