I had a Hoover self propelled upright for a long long time. My dogs were terrified of it. The dog in my avatar, King, was scared of only two things, that vacuum, and a ceramic cocker spaniel that could outstare him. I always thought the vac scared him because of the noise, it was very loud, and I never really liked it because of that, and it threw out an amazing amount of heat. I used to take King to work with me, and one night the cleaning people were running late, and I saw they had the same exact model vac that I had at home. I expected King to go into a panic, but as the vac got closer and closer, he didn't seem to be stressed at all. When she got to the point of it being right next to him, she started nudging him with it, and saying, "Come on honey, move over!", and he just laid there. Finally I just slid him over about 5 feet and she vacuumed where he had just been. I took the hose attachment and ran the nozzle up and down his side and he barely blinked. At home, panic ensued as soon as I took it out of the closet. When it broke, I bought a refurb hoover bagless upright and a Dyson cordless. Both of them were ignored by my dogs for the rest of their days.
I have severe back issues and vacuming is about the worst thing I can do to myself. I did some Tuesday and an only now recovering. The Dyson is my preferred machine, but it's capacity is low..