@ibchert, I seriously doubt you get any new technology being tested out for the next generation in the last year of production of the previous generation. Name some examples.
Examples? No .... it's just an impression I got. When I looked at the 2015 there seemed to be features I hadn't seen when I looked at the 2013/14 models. Still think it's a valid possibility but I guess I don't care as much about such things as most on this site? I do, however, love my Prius (and the one before) so that's why I'm here.
I've had my gen 3 for almost 3 months now. I had some buyers remorse and jealousy seeing all the gen 4 excitement but it has subsided. I'm still happy with my decision to go with the leftover model.
Under my criteria, GEN III has been the best line of the Prius hatchback models, with the exception of my former 2012 PiP paint finish
The flying buttress is functionally brilliant. If it's functional, then it cannot possibly be hideous. I'm constantly switching between EV and HV mode, and Neutral and Drive. Is the gen 4 as easy to access? Items like phones stored below the console are mostly out of easy sight, so they become less enticing to thieves to break into the vehicle. Sure, I could store things in the armrest console, but it's just slightly less convenient. Concerning the gen IV; I'll have to take one for a test drive someday to compare it. From what I see from a technical standpoint, it seems to not be much improved over the Gen III. The standard gen IV models get the same EPA fuel economy as the gen III, and the eco version gets better economy from yet to be revealed magic.
As a total Prius/hybrid newbie I cannot talk to the style/mechanical changes between gen 3 and 4, but the 6k differance between the two is what helped me decide to go with a 2015.