The new Physically Based Rendering pipeline in Unity 5 is really nice. One shader - the Standard shader - gives you settings and possibilities that cover most material needs. It easily outweighs the legacy shaders in terms of convenience, possibilities, ease of use and flexibility.
There is, however, one caveat; to fully utilize the new rendering technology you need to start thinking about color spaces and color correction. For me personally that is not a big thing since I have a background as a graphical designer and photographer where these things are part of your everyday workflow. For the novice it can take some time getting into, but it is totally manageable.
To use the full potential of PBR (Physcialy Based Rendering) in Unity you will need to work in linear color space and check that little HDR checkbox in your cameras. This also means you have to use the deferred rendering path. And this is what gives me a bit of a headache. Just plain changing my previous setup to one that uses deferred rendering means I lose performance and thereby framerate. Since SpeedTracker is very dependent on physics simulations this is not very welcome.
I guess this is where I need to start digging around to find the best compromise between utilizing the new rendering technology and keeping enough CPU and GPU resources for my physics simulations. It will hopefully be an interesting and educating journey.
It would be interesting to hear what experience others have in this area.