Changed from the W204 C200 diesel a month ago. First trip was across the UK putting up 1400 miles in a weeks driving, an mix of motorway and A class roads. I have to say the car never missed a beat. Motorway mileage was 62 mpg while mid 50's was the norm for lesser roads.
The interior is indeed a lot different to the earlier model with the gear change lever on the right of the steering wheel. The tablet display does take a little getting used to and really looks like an after thought, it would have been much better if it had been built into the dash. All the controls for heating etc. are easy to reach but the "mouse" pad is something I doubt if I could ever use on the move. It seems more of a gimmick than any real use. Unfortunately here in Ireland no sat nav is fitted to the "poverty" models nor is the SD card slot fitted so no chance of a retrofit.
So far the car is great but not without faults. The light switch keeps getting moved from auto to on and there is a wind noise on the passenger side, but the worst is the horrendous road noise at anything over 100 kph from the Continental tires on motorways, hence the low rating for ride and handling. Another source of annoyance are the juddering noisy wipers. It's back to the service dept. on Monday, hopefully these will be sorted then.