Dumb question that I don't think I've seen specifically asked, but why are these Professionals and not Ultrasharps? Is there a specific, hard reason for the difference between the two lines outside of something like warranty?
It's quite odd these aren't in the U category as they have the same warranty as the Ultrasharps and the viewing angles/color specs are as good as monitors like the U2713HM.
Sometimes the number of ports and features (e.g. built in USB 3.0 hub) are a differentiator, but even that doesn't seem the be the case this time.
Maybe Dell is shifting their product lines around a bit as 4K and 27" becomes more mainstream? Maybe we'll see some nice priced 32" 4K U Series soon
Or it could be something really pragmatic such as the percentage discounts they offer to large business purchases being different on P and U series.