Hi -- Will be in Cologne for just one night in early December (quick trip from Paris) to hit Christmas markets, walk around old town, soak up the atmosphere, etc. Have points to use at either Marriott or Hilton but can't decide between them. Reviews seem marginally better on the Marriott, but the Hilton seems to have a better location (and sounds like a good gym). Can I really go wrong with either one? Thanks.