My partner and I stayed in David's apartment for an evening and found the stay fantastic.
The flat is spacious, clean and modern, and David as a host was helpful and accomodating, including making sure the heating was on for our arrival, which, given the temperature when we arrived, was greatly appreciated.
The flat was situated in an ideal location just off the grassmarket, and though we mainly used the flat as a base, if we had been staying longer it would have been perfect for having home cooked dinner.
The flat was immaculate and well presented, and the bed was extremely comfortable. I had seen reviews mentioning the noise levels, but didn't find this to be a massive issue - there was some evidence of the nightlife on the grassmarket as you would expect but it wasn't nearly as loud or distracting as I was led to expect!
I didn't wait for a response from David for any longer than half an hour, which is impressive! Overall, hugely impressed and would happily stay again!