most city buses are low floor and geared for city driving, I personally think anything faster than 60mph in a heavy bus is too fast...call me old fashion; whatever
now having excess power for the mountains is something different!
basically decide flat nose or dog nose (they drive different and turn different)
front or rear engine (rear normally has bigger engines and more OTR features like being able to add jakes) they also have a lot of under belly storage options
body names don't mean squat really (except for Crowns and Gillags)
the carpenters that had issues with roof collapses are (or should be) off the road or fixed (I would still not want one tho') and it was only buses manufactured at just 1 plant (I have posted many times how to tell them apart from other buses)
I will not argue the build differences of all the buses out there; they all are built like brick crap houses
so everyone here will have an opinion of what has worked out the best for them...
hope this helps