Life is a trade off. Do you want to use storage space for a large tank on a machine that you seldom use or do you want a small machine that takes a long time on the rare occasion that you need it?
I carry the small one. Yeah, it takes awhile but I am in no hurry to go anywhere so I plan its use accordingly. Works great for tires, blasting dust around in the basement moving it from one hard to reach spot to another & makes an excellent redneck fire starter for those stubborn fires that need some help with supersized lungs.