it's actually much more complex than that. there are at least 4 classes of trains (regular, fast (k), especially fast (t), nonstop especially fast (z)) and 5 classes of tickets (hard seat, soft seat, hard sleeper (bunks stacked 3 high), soft sleeper (bunks stacked 2 high), and deluxe soft sleeper (only 2 beds per cabin; sometimes stacked, sometimes not)).

there are at least 5 z trains between beijing and shanghai (each direction) leaving between 7p and 730p. ime, they are never more than 2 or 3 minutes late because they all run together (in addition several other z trains between hangzhou/nanjing and beijing and tianjin and shanghai).

some of my friends think my odd preference for train travel is crazy given the fact that taking the train entails missing out on: 1) a night out; and 2) the chance to ride on an airplane, which they know i love. well, let's just say that i continue to perplex them. in fact, i think i took the train at least 10 times last year (lost count after around 6). if you do a search for {"z train" beijing shanghai}, you can read the trip report i wrote after my first nonstop.

back to the subject of hotels, pm me if you need help picking a place and don't be frightened by ptravel's $100 quotes; i promise you can find comfortable digs for much less.