McD fries are, hands down, the BEST fast-food fries around.
And I worked at McD for 8 years (fry cook to manager from high school through college and the start of law school). The fries take 3:30 to cook, exactly. In for 15 seconds too long and they're burnt. Take them out 15 seconds too early and they're limp, soggy and underdone. This fact alone was always disturbing.
Once out, you HAVE to properly season the fries with the special salt (it's really just salt with a few other ingredients in it). If the fries are not salted within 30 seconds, then a chemical "bonding" doesn't occur and your fries will look like they had powdered sugar (white specks) sprayed on them. If properly done it forms this "glaze" for lack of a better term that is undeniably addicting. The classic taste.
For the record, eating a fry BEFORE the salt/glazing is horrible. Bland and actually affirmatively unpleasant tasting. With the salt....you all know how good it is. oh, and the fries that sit in the "fry bin" have to be served within 10 minutes or they're thrown out. Literally, every McD's trash can near the fries has pounds and pounds of otherwise perfectly good fries in it because their "life" is only about 30 minutes total. We assume you eat the fry within 20 minutes. If not, you're SOL. Reheating doesn't work, and refrying (dipping old fries back in the grease bin to heat them up again) creatse the biggest disaster you've ever seen (aside from being grounds for immediate termination).