Once I'm asleep, I can't tell the difference between a Motel 6 and a Four Seasons. Thus, if all I plan on doing in a particular city is sleeping (say because I am driving from Point A to Point C and along the way have to stop in Point B) then I am going to be looking for the least expensive place I can find that will give me a reasonable likelihood of being able to sleep well. OTOH, if I am going to be in a city for a few days, then I will try to find a nicer place to stay, one that has a pool, exercise equipment, high speed Internet access (preferably free) and a good desk in the room. But even when I am going to be somewhere for a while, I still find no reason to stay at the high-end properties; usually a well run Hampton Inn is all I need.
If I am going to be at a convention, I will try to stay at a downtown hotel within walking distance of where the convention is at, but, when I do so, I almost always pay with points. If I can't do that, then I instead usually stay out in the suburbs and drive in each day in a rental car.
If I am going to be somewhere for a week or longer, I will stay at someplace like Homewood Suites (if using points) or Suburban Lodge or Inn Town Suites if not.