It is fast, it is silent, it is great.
I bought the OM D E-M5 when I was in New York just before Sandy. And a day later, I bought the 75mm. I had a GH2 that I gave to my daughter. The combo; OM D E-M5 with the 75 mm is great in low light situations. With a gorilla pod, you can shoot literally anything at night. It is sharp, noise is low even at 3200 ASA, with the Art Filters of the camera, even the dullest scene looks interesting.
Highly regarded, strongly suggested as an essential.