A lot of people feel that moving from cover to cover goes too fast, the Ghosts shouldn't be able to sprint so fast. But is it really so bad? There are a few earlier videos with really fast sprinting animations (especially the firefights on the street in Peshawar spring to mind), but in most other videos, it doesn't seem so bad to me. For example, this video at around 3:30 there is a really clear sprinting animation. It doesn't seem so fast to me. Or this video at around 2:40. I think this isn't a bad speed for cover swapping, it might be faster than most people can run in real life, especially considering the amount of equipment they are carrying with them, but one has to consider the gameplay too. And besides, I think this running speed is pretty close to how fast you could run in GRAW and GRAW 2 (PC version at least), and there you also had an infinite sprint.
Btw, this video show some insanely fast sprinting animations. These animations I do agree are just too fast and you seem to be able to cover-swap without any chance of getting hit while you're doing so. But it seems, looking at other videos, they toned it down, because the other videos I linked use a lot slower sprints.