Picked up an ex demo smart for four ed in April and have been runner her about the last few months and comparing it to my bmw i3 2016.
Impressed with the little car and it works well where we live in the UK , we decided to sell the i3 and the little smart has become the main daily drive.
Things against the i3 where the poor visibility at junctions , small boot and the interesting driving characteristic of the skinny 155 tyres , in the wet the front understeer was bad at speed and the rear wheelspin was also an issue , great car for me to drive but the otherhalf had too many close calls driving the thing. Also the poor bridgestone tyres , after two years they had badly cracked and crazed , not impressed.
The one big thing i'm missing with i3 compared to the smart for four is obviously the range and the power , the smart feels very under powered and needs charging every few days, also the home charger is very temperamental and never charges at full rate , it tends to drop back to 8A charge and get really warm. I tried the i3 charger on the smart and it had no issues of charging at the full 10A without issue.
However the biggest shocker is the twizy is still my favorite electric car with the power box.