I haven't stayed at the ORD Courtyard, but I have stayed at the ORD Marriott several times (last stay was about 3 months ago) and I enjoy it, with the exception of the shuttle from the airport. However, I think that any hotel shuttle from ORD pretty much s**ks because of the airport layout and the general infrequency of the shuttles.

Things that I like about the ORD Marriott:
- Concierge Lounge & breakfast - nothing spectacular, but the folks who work it are quite nice and more helpful than most lounges I visit
- Workout room - very important to me and quite good for an airport location
- Rooms - new beds, good internet access (for a $) and spacious
- Plane spotting - it's an airport hotel so you get planes landing/taking off right over the top of the hotel from runway 27R/9L at ORD. I love this and I always carry earplugs for when I sleep.
- Front desk people - they are not the most polite, but they are darn efficient and the do not let the aircrews cut in front of Marriott Rewards folks w/ status

Things I don't like
- Shuttle - see above
- Outside of hotel - I don't have to look at it much, but it is pretty darn ugly