Mark is absolutely fantastic, very easy to get a hold of and flexible. We were in Denver for a conference and needed to check in & out at different times than "normal" guests due to our schedule. He was more than accommodating and even jumped on the call to discuss the process in detail.
The neighborhood is a stark contrast to Mark's place, but that shouldn't deter you from staying here. This is the ultimate pad with everything you need to have a good time in Denver. Close to downtown with enough room to fit multiple people without feeling cramped. We absolutely loved it and hope to come back.