Shotguns have been slowing D2's play down for awhile. In order to counter a shotgun without using one, you find yourself playing more campy and laid back. I've been kinda over PvP for awhile now, only playing for seasonal challenges or pinnacles, but special ammo in PvP has been a big thing turning me off.
It depends on the platform from my experience, on console, I find things to be paced a little bit slower, people can't wip a 180 in .2s and positioning is somewhat important.
On PC we have insane movement and maneuvers we can pull off. This can throw logical common sense out the window more often than not and allow people to ignore tactics and team play. Before the cryoclasm nerf, I could slide in and get 3 kills on a group that knew I was coming just because of nutty movement. Had it been a controller, I doubt I would be able to change 3 directions in rapid succession without dying.