In an episode of Grimm there is a particularly nasty Wessen that resembles a fly who can blind people with parasites that eat their eyes. When Nick is blinded he is able to hear EVERYTHING he can hear people over the phone from metres away. When he regains his sight Monroe is throwing fruit at him while he is blind folded and he hits all of them with his bat, implying some sort of super sense? But after this episode there has not yet been another reference to this ability? Was this just an episode thing or have I missed something?
Nick's senses, including his hearing, sight and overall proprioception (awareness of his body, its position and things around him) have increased significantly.
He is stronger, a bit faster, far more formidable than he had been before transformation. I suspect the powers only manifest when he is under extreme physical duress.
Since the event, he has been tested for his overall health and his doctor has been unable to explain his incredible endurance or lack of increased cardiac activity while taking a stress test on a treadmill.
He has not been blinded since his transformation so we don't know if he can use his senses in their enhanced mode or if he is capable of using his "fruit ninja" powers again, but the arc of the show seems to be developing his character's physical abilities making him the dangerous being, the Wesen seem to consider Grimms.
We are also unaware if these abilities are native to all Grimms (but considering his mother in context) she is a fantastic fighter despite her advanced age. We can assume, the powers may take years before they completely manifest.