I agree with iwinit that a lot of the jerkiness can be attributed to the transmission. One thing to keep in mind is that the ZF transmission constantly downshifts as your speed decreases. This can attribute to a slight jerky sensation when slowing. The advice about gradually decreasing braking force prior to coming to a stop is helpful too. Definitely takes some getting used to.
While on the brake topic, has anyone noticed the difference in initial brake bite when you lazily move your foot from gas to brake pedal versus when you rapidly move foot from gas to brake? As they described it to us at the PCD experience, if you move your foot quick enough the brakes 'pre-tense' in anticipation for an emergency stop situation, which in my opinion is a very cool feature and works really really well on our X3. The thing is, if you go fast enough from gas to brake, in a non emergency situation you can still trigger this initial aggressive bite and the results can be startling.