Been riding some Freeriders for about 2 months now. Very happy with them, and find the grip fine for me with Shimano DX flats, except for rocky climbs where I can get bounced off a bit. However I don’t do big drops or jumps.
Difficult to compare as they were my first venture away from SPD’s. Definitely not as stiff as the SPD’s of course, but I have not been noticably slower up hill, and find them really comfortable. As The Doog said, they actually look pretty cool, whereas if you wore Impacts to the pub you would need extra length trousers with big flares to try to hide them