Genghis i think you will find the faa ir is every bit as hard as our equivalent - some would say "harder" some would say the emphasis has far more to do with real world application. I dont think anyone seriously argues these days there is much between them. In fact the evidence is faa ir holders in europe have a lower accident rate than jaa ir holders. I dont think the cat enviroment is relevant - instrument flying in a multi crew commercial cockpit is very different than single pilot ifr ops. One might say single pilot ops with a six pack and no ap outside cas is as tough as it gets. Some are even currently questioning the instrument skills of certain french atpls at the moment.