That's really really common with Japanese as well. 80's are just too long for people under 5'xx" to carry arms extended, and then it's a real bear. I spent a couple of days trying to see what it would be like to have to carry tanks like that, and I realized that I would never have been able to become an instructor if I had to carry the industry standard 80's like that. Most Japanese instructors do OK with little tanks but 80's are a fight to handle for them.
On the other hand, to keep up with Japanese diving 80's, I need to carry 120's and those are a fight for me to carry in the arms or on the back.
And that is where sidemount shines. To match up divers, another 80 can be added to the mix for whichever diver needs it. I can carry 3 80's easier than twin 120's, and that is even with them hooked up SM or carried one by one.
How is it for you to carry two sidemount 80's if they are hooked up to your rig?