I have 2 medium carriers. I thought I had issues with the bowls but hubby figured it out. They're not as easy to sit in there as i would like, but they work. I love using the cages to give the zons a bath outside in the sun. Of course, the rings rusted that hold the bowls but hey, those can be replaced.
A grate and a tray is nice in my opinion.
I love having food bowls in the carrier. When I was kicked out of house during the remodel, my sister-in-law was able to change a dirty water bowl and did not get bit.
I have an old model small and the floor moved in that one. Also, it didn't have a grate.