I would say they are WAY more comfortable than a normal school bus seat. Honestly I'd never been on a school or transit bus before with seats this nice. If it was on my local route, I'd probably be really happy every time I got this particular bus. Unfortunately for my build it just doesn't make sense to keep any of the originals.
In terms of "thin"-ness, I don't think they are thinner than normal school bus seats.. I could be wrong. They are certainly much thicker than the usual hard transit bus seats, in any case.