As in my reply to Ragebeard, R&D will likely be almost the same, nothing major changed apart from manufacturing upgrades after researching them but essentially its the same to me.
Its amazing that they put effort into training the AI to race circuits backwards but going with more upgrade options for a broader variety or actual depth to career mode or to let them have tyre temp simulaton is nothing they want to implement..
You can expect the exact same changes to car handling from upgrades as in the years before, its a shame there is no better explanation as to what changes and probably same problem in the setup menu where especially new players would need a proper guide as to how each setup option changes which behaviour of the car at which point on the track..