I think the power steering feels different in the 2006 also. Not as light as before which some ppl might like. Some people were concerned about drift in the earlier years but 2006 tracks really well hands free even at high speeds. The rear camera is neat-o, but has pretty minimal use IMO. Looking over the shoulder is still much better in almost all circumstances. Some people it's good to avoid small children. It's a little helpful reversing from parallel parking to detect oncoming traffic but still have to look over the shoulder when moving imo. A good addtion but nothing to really miss either. Voice commands are nice, but the system is too verbose imo. Also, the only annoying thing about the many steering wheel buttons is they rotate with the wheels so difficult to use unless going straight. A wheel center which remained motionless would be a good design and also allow for driver airbag to be other than round.
Overall though, I like that the Prius design philosophy is to make a great car technologically and stylistically ahead of the curve and then do major design overhauls periodically rather than constantly trickling in changes to a muddled and overworked design as most cars are.
For example, some people don't like how the Prius looks because it's not following the latest automotive fashion trend which is mostly animalistic design or Passat design. So what? Like boxy or round the new trends quickly pass and then be recycled beyond product lifetime just like fashion and bellbottoms.
The 2004+ Prius design is about streamlining and maximizing interior space, form following function. I think it accomplishes that successfully and the design has tremendous integrity and a timeless quality. I’d compare the Prius to the best Frank Lloyd Wright buildings for example. I'd compare most cars, American in particular, to the new prefab buildings with bolt on neo-colonial facades and moldings. U-G-L-Y self contradictions.