I'm sure mcdonalds fry quality is dependant on location, time of day/how busy they are. If they are fresh they are good, but the problem around here is that they are hardly ever fresh when I happen to go there so I get a bad impression and never eat there. Our wendy's on the other hand always has fresh good fries.
Btw they no longer need supersizing as they have been cutting out all the smaller sizes and upping the prices. Your gonna end up with supersize anyways they'll just call it large and charge twice what they used to.