I think their are some situations where a Courtyard and a nearby Fairfield are fairly comparable properties. And the OP may have encountered several of these situations recently. However, it total, Courtyard is a superior product to Fairfield.

I've found that the Courtyard product is much more consistent. While you do occassionally find one that's a bit rundown, for the most part they are relatively nice, have a nice pool and workout area, etc.

Fairfields, on the other hand, are much more of a crap shoot (and I'd put Hilton's Hampton Inns in the same boat). You may luck out and find one that's real nice. Or you could reserve online and find yourself in an exterior-corridor dive.

My impression also is that the construction quality of Fairfields is a notch below Courtyard. So, if you compare a new Fairfield to an old Courtyard, the Fairfield may be comparable, or even better. But, give that Fairfield 5 years, and it'll be in the same shape as the 20 year old Courtyard down the street.