On long haul people normally carry a fair amount anyway - they'll try and get as much as possible in the cabin but if they can't it'll go in the hold.
You might have an effect on SH Business flights but these days every flight is full of people carrying big cases it seems - so no saving
I once traveled to Schipol carrying just a newspaper and the hassle was ENORMOUS..................... everyone assumed I had forgotten my case in the terminal somewhere, or was a terrorist or some sort of weirdo..........