I too think Jazz brakes are snatchy, you do get used to it if you drive only a Jazz, but when you also drive other cars the snatchiness remains noticeable in comparison. Have you considered that perhaps the front/rear brake balance is incorrect and that most of the work is being done by the front brakes. This might give the feeling of the brakes grabbing as soon as they are applied, try applying the handbrake on the move and then braking, if the brakes feel smoother it would indicate that when the rear brakes actually do some of the work it gives a better feel to the overall braking. I've noticed rear disks corroded on Jazz's, maybe due to poor quality steel, sticky calipers or just very light usage that never really puts the rear disks under much pressure, however the bigger front disks, carrying more of the cars weight will remain clean and eventually you can get effective front brakes and less effective rear brakes. Don't really know why Honda think the Jazz needs rear disks, wonder why other similar size cars stick with simple and effective drums at the rear.