This weekend I added motion blur in my engine. Initially I didn't want to have this effect at all. Usually I find it ugly/noisy and makes me a bit sick. There is one game however where I actually like it: Syndicate (2012) !
In this game, the effect is only based on the camera motion, and only when moving very fast. So it triggers only in specific conditions, and doesn't impact gameplay much.
@froyok interesting! i find i prefer motion blur the other way - none on my camera movements, only on objects moving

@andicraft I think my problem with that is that it become difficult to make it look good. You have to handle sample rejection for objects moving behind static ones, dither in case an object motion is too wide, etc.
Plus during gameplay I like being able to still easily track moving target.

I guess it's a matter of taste and habits. :D

@andicraft I guess I focus on the "I'm moving fast" vibe instead of "that object is moving fast". 😄