Where should I stay in Bonn or Cologne?

I need to be in Bonn for business, but figure I can get the train from Cologne.

I'll have time spare in the evening before the work, and the afternoon and evening after the work.

tbh Bonn looks a bit dead... so I'm very tempted by Cologne.

Is there a queer part of town where I should look for a hotel? Anyone have a hotel recommendation? Restaurant recommendation (I'm gluten free)?

@dee Cologne is so close.... and yet so far... Maybe next time! ​
@hannah oh, where should I book travel to next time?
@dee Hannah lives in Hamburg. Anything in somewhat close proximity would induce a visit by this entity! ​
@hannah oh yes, that's a bit farther out... I occasionally do Berlin too (ugh, the airport!)... and occasionally Copenhagen... none seem useful, you're equidistant from all the boring companies I need to visit.
@dee A daytrip to Copenhagen could easily be arranged! ​
Or to any other city in Germany really... Just requires some planning!