If it feels choppy, as you describe, or like a pulsating, the one thing that would come to my mind right quick would be warped rotor(s).
Try getting the front tire of your bike up off the ground, and get to a vantage as to where you can at least see one (if not both) of the brake pads where the rotor come through. Now gently spin the tire and see if you can see any variation in the gap between the pads and the rotor. If there is, I don't care if it's a fraction, then your going to have to replace your rotor(s).
Also check your rotor mounting bolts. Are they loose or missing? How about your front wheel mounts, are they loose?
It could also be front wheel bearings going bad.
Make sure you check your mountings and bearings before you do the rotor test as any of these will cause the gap between your brake pad and rotor to vary.