I've never been one to follow the pack so I went aftermarket
Actually I went that way for a few reasons:
-no F-150 logo. Remember I'm REALLY tall, so its kinda directly in my peripheral vision since I sit up rather high. With it gone more light is being let thru. Its a subtle thing, but for me personally the difference is obvious.
-the guarantee; the installer reiterated that if at any time, for life, if I find something I don't like, he'll come out and replace it with the OEM for only the additional cost of the OEM shield over what I've already paid for the aftermarket. He'll cover labor. Hard to argue with that.
-when it got here we talked about the differences and we both looked at it really carefully. I just can't tell any difference in clarity, consistency, color, thickness... they're the same shield.
PS: If you ever need to replace your windshiled and you elect to use a mobile service, do them the favor and make sure they understand the truck is "lifted". I had done so, and when the guys got out here they were VERY glad I had, since they had brought extra ladders. Without those ladders they couldn't have done the work.