I've stayed in all three of those.

My SHS Addison experience was actually pretty good - liked the hotel, liked the location. Well, given that it's in the middle of a Texas suburb...relatively speaking, it was nice to be able to walk to a bunch of restaurants/bars. It seems to be a newer build...I would think that maintenance issues, over a larger sample set of stays, should be minimal.

CY on Midway: stayed there about three times because of insanely low rates - AAA rates listed in the $42-45 range. Yes, it's dated...but I never had a problem there and actually got a suite two of the three times. The place always felt dead to me - few guests and it's in the middle of an office park, so there's nothing going on around the property.

The other CY is a dump. Since you're probably filtering on the cheapest possible Marriott properties in the area, you probably also saw the Courtyard LBJ: that one is a dump too...but I still hit it a few times in the summer of 2010 for the cheap rates and the Delta promotion. I saw police activity in that hotel parking lot more than once...and even more often in the run-down apartment complex next door. On the bright side, if you need a check cashing store, a payday loanshark, or a pawn shop...you've got 'em within walking distance.

If you want a cheap Marriott that's pretty nice, go a little north to the Courtyard on Preston in Plano (I think). New lobby, very clean surrounding neighborhood, walkable to restaurants/bars. They sometimes give "bonus" amenities to Plats - a bistro appetizer or a free drink, for example. Maybe 10-15 minutes from Addison itself.

On the bright side, I had good experiences at most of the full-service Marriotts in the area. In off-peak periods, many of these will have very attractive rates. The FS hotel rates would drop well below the Residence Inn rates. As such, although I hit most other Marriotts from downtown Dallas to Plano at one point or another, I never stayed in the Residence Inns.