Just wanted to log in my experience and thank you for your help.
The Mercure was clean and modern, with a lovely rain shower. It's also right across from the KLM lounge. However, there is massive construction at AMS which resulted in massive noise, I mean like jackhammers, starting at 2 AM. I would not stay here again till this construction is over, sadly.
One tidbit: since I couldn't sleep, I went to the KLM lounge at 4:45 AM upon opening. I saw the lounge ladies taking drinks out of the hands of some young folks who seemed to be there after some massive all-night partying...
Thanks again.