Before I got it, I was like meh, what would I need a 40mm f2.8 for.
Then I got one..
..and absolutely love it!
Barely use it though, but it's still great for those situations where I want to bring my camera but don't want to lug around a huge lens with it.
It's awesomely sharp, even wide open, contrast is great and focuses quite fast.
Highly recommend anyone who doesn't have one, to get one.