If you want to travel from Hangzhou to Suzhou (or the other way round) try something special. Of course you can go by train, bus, and so on....even faster.
But I think the Emperors Channel is more adventurous and also a nice change from regular means of transport. In past times it was possible to go all the way from Beijing to Hangzhou on the Emperors Channel.
Today the boat leaves in the late afternoon from Hangzhou and arrives in Suzhou in the early morning. You can choose between luxury double rooms with the best view on top and 4 to 6 and even more bed cabins below deck. As far as I remeber I paid 60 kuai in a four bed cabin under deck, which means you have two portholes or windows just over the water level.
Well, beds were a little bit short for my size - but that happens in sleeper trains, too.