From all reports I've seen on Urbom, his skillset is precisely what the Caps have needed for a while. Sounds like he's a steady defensive-oriented blueliner with good 4-direction mobility and size to make things difficult for the enemy in the Caps' end. Straight line speed isn't as important for a Dman as is the requisite footspeed to provide the short-area quickness needed to stay with attackers below/around the goal line.
Plus, he's still only 22. His prospect reports all say he has shown flashes of additional offensive upside. On the whole, Dmen take longer to develop their games so I'm hoping for better things from Urbom down the line offensively. If not, he still projects to be a steady 3rd pairing defender, which is something all the other guys the Caps have trotted out have yet to shown any sort of consistency with.