Purely from a passenger perspective.
Just had my first rode in an Ioniq Hybrid Singaporean taxi.
It looks a smaller car than the default i40, but even though I’m almost 6’3” I had plenty of legroom in the back, and although I was aware of the lower roofline than in the i40 I had plenty of headroom. There was enough width for a third passenger in the back too.
Ride was fairly firm, but still comfy, and it’s a quiet car.
It was pretty new, only 25000km on the clock. The i40s do 20x that before they get retired. Drover said the running costs were lower than the i40 diesel with the hybrid’s better fuel economy in the city.
Will post an update if I go in one with a more typical high mileage.