I only took one overnight bus, and it was hilarious. It was going from Jaisalmer. Sadly, I can't remember which sort of bus it was, which isn't very useful for you, but it definitely didn't look like the photo above. My friend and I were in a little glass-fronted box compartment that we had to climb a ladder to reach. There wasn't space for us to sit up. We could just about lift ourselves up on our elbows, and we lay down with our feet at each other's heads, because it wasn't really wide enough for us to lie with our shoulders next to each other, either. I don't remember much about the journey itself, which I think is a good thing - there are no horrible memories that have seared themselves on to my consciousness. It wasn't a very long journey, which I think made it better, too. I bet I'd have clearer memories of it if it had been one of the really long trips. Whichever sort you end up with, it's definitely better than the ones where you just have seats. Those can be really, really uncomfortable, particularly for long periods of time.