Smart Dealers - After Sales, What are they like?

Am interested in the #5 as it ticks most of the boxes for a family size vehicle. Only thing is that ideally I would like a car with more warranty, at least 5 years so I can have that long worry free. However, no manufacturer comes close as a car. So willing to accept the 3 years the Smart comes with.

For those currently owning a Smart Hashtag of any number, what has your experience of the aftersales at dealers been like with Smarts electric range of cars? And the service costs (if paid for?). Previous Mercedes experience was never great and even now approaching dealers to look at a #5 as been pretty poor.