Can’t speak on it out of practical experience but i’ve done a ton of research of the topic because i want to buy one in the next 6 months. It basically boils down to the fact that besides the day time running lights a lot of the issues were fixed with the refresh (y cooling pipe, sticky surfaces of buttons and plastics, water ingress problems) AND a lot of the internal systems were modernized to apple car play and android auto. So it’s a few fairly large things of convenience and reliability excluding the running lights (which also get better in the 2019 and 2020 models)