ya there is a huge difference. that thing near the top by the funny-shaped thing is different. the kicker is that the backside of the small part is totally redesigned. I almost forgot......the colors are different too.
The only difference is like kristian said, the footbed is different. The 04's have a contoured bed so that it is more ergonomical to the balls of your feet. I have the 03's and my wife has the 04's. She hasn't ridin them yet, but I would think that the countouring would be nice. But I have ZERO complaints on the 03's, I love them.
On the reviews for the parks bindings there alot said of them ripping and what not does this happen to many people and have they made improvemts in the rubber or something to stop this from happening
I haven't had any problems with mine (03's). I have heard a lot of people say they have had problems, and have also heard a lot say they have had no problems. I believe someone on this board said that the majority of the problems came with the 02's? But I am not positive on that.
the 2002 HL bindings were the ones with "issues". They didn't have the curing times for that compound right, so that lead to a weak overlays. I've been through one 03 parks overlay, but ifyou take good care of them, I don't think you'll have problems, anyways HL is usually pretty good about replacing that stuff.