Sturdibag Airline Seat Under Has Anyone Used SturdiBag Pet Carriers For Flying W/ A Dog? Wonder How Sturdy And How Well They Fit Under Seat?

Has anyone used SturdiBag Pet Carriers for flying w/ a dog? Wonder how sturdy and how well they fit under seat? - sturdibag airline seat under

I have only Teafco Argo dog and I was very happy with it. But SturdiBag seemed to take a dog into space. Would require the size and wondered how well it fits under the airplane seats. And do not look as strong as my school bag, but it can be.