I've stayed at both the Crowne Plaza and the Marriot New World. I actually liked the Crowne Plaza much better - it is in a better location for just walking around and seeing the city. The area around the New World isn't as pretty, interesting, or as pedestrian friendly. Being close to some attractions isn't a big deal because taxis are very very cheap in Beijing. Our room in the Crowne Plaza was considerably larger (3x?) than the room we received at the New World. Both hotels were nice, and the New World was cheaper. I think I paid about $80 USD per night for the Crowne Plaza vs. $55 USD per night for the New World (both internet special rates). I also found the the staff at the Crowne Plaza spoke better/more English than the staff at the New World - and given the state of my Chinese speaking ability, this was pretty important.

Sites to see: Almost everything we saw was in the guidebooks. We visited in the summer so spent time in parks, etc. which may not be very attractive for a winter visitor. I wrote a lengthy trip report. If you'd like a copy please feel free to email me and I will send it to you.