Airport to downtown is about 16 miles, Mars 4pts. is about 20 miles. But from the airport you need to go through the tunnels, which has traffic about 12 hours a day, up to 30 minutes during rush hour. Mars has maybe 10 minutes of traffic at the peak of rush hour, nothing at other times.

My house is about 4 miles away, so I've never stayed at the 4pts Mars, but it used to be a Sheraton, has several shops in the lobby, including an upscale jewelry/watch store, and seems nicer than the average 4pts I have stayed in.