I also have the Victornox 2.0 20 inch bag. I just packed it for a trip that was cancelled due to the awful weather. I holds an amazing amount.
This bag was a corporate gift and I never packed it until this week. I have that much luggage.
I absolutely agree that we need to learn to live with 20 inch carry on bags.
RedOxx which makes both the Air Boss and the Safari Beano 5 (and many other items) lists the capacity of each bag on their web site.
www.redoxx.com
My primary checked bag, a 24 inch Delsey, was destroyed by an airline baggage system a week ago. I've been baggage shopping all week. Here's what I've been doing in brick and morter stores. I pack up my packing cubes with exactly the amount of stuff I plan to take for travel and do trial packing in the stores. No one has objected. I had believed that I really needed a 24 inch wheeled bag, but I've learned this week that I can get along with the Victornox 20.
I strongly advise people shopping for luggage to carry along their own tape measure as the hang tags on the bags are not always accurate and some include the wheels and handles and others do not.
If you don't want to take along your clothes and other gear, pack your packing cubes or even plastic bags with packing peanuts and see which bag works for you.
I am seriously considering RedOxx's Safari Beano 5 for overseas travel as I can manage the weight and it is a good size.
Good luck in your shopping.