I am a little confused by your post. How does not checking a bag impact the hotel choice? Where do you want to stay? Moxy is at the airport...Courtyard is near the Messe so a totally different area. Early check-in will not be guaranteed at either hotel as a Platinum so checking in early is a game of luck at either hotel depending on the previous nights occupancy. (only way to guarantee a room being available at that time is to book the previous night and inform the hotel of your arrival time)

IMHO neither hotel is a good option if you want to see the city but you are not clear if you want to transit to sleep or sightsee. If it were me and I was picking between only those two hotels.... I would likely pick the Moxy and take the non-stop train into the city for the day. Neither hotel is going to get you much in elite benefits.