Originally Posted by Proximity

Well Falcon's are engineered to fly nice while Bombardier doesn't care.

You're probably trying not to overcontrol, but the 604 has stupid small ailerons with no spoiler assist, and the gear doesn't like side-load. Likely you need larger and more aggressive roll inputs. Wing down top rudder and don't try to hold it off in the flare because you can run out of aileron.