Join Date: Jul 2010
Location: Shanghai (PVG/SHA)
Programs: SQ Gold, AF Platinum, AA Platinum (sadly, expiring soon), QR Silver, EK, MU, HU, PR, HO, OZ, KE
Posts: 685
I think Nanjing would be a good destination if you really want to feel the speed of the HSR. If you go for a nearby destination like Suzhou, the train doesn't really have the time to get up to speed before it has to slow down again, and it's not really value-for-money.
Round-trip 2nd-class tickets for Nanjing (about 1+ hour each way) will cost around 300 RMB/pax.