^If the interior is not to your taste, it does not mean that the quality is poor.
I do not own the car, but please talk of low quality if u have issues like rattling, loose bits or bad assembly or installation.
I dont know what u mean by lightweight, but its a well grounded car and u dont get the feeling of flight at high speeds.
Mileage is one of the best amongst 1.3 litres in the country. The engine is preppy too.
By durability, if u mean body strength like old cars that you would like to ram into poles with no effect, then no, not durable at all.
Newer cars are built with passenger safety in mind, and the whole car is designed to take the impact and crumble to save YOUR life.
So u can call it katchi and halki and easily damaged, but these very things will save your life.
Regarding everything else, I believe any car is durable if u take car of it. Change oil frequently and keep the liquids in check, perform periodic maintenance and I see no reason why the City will not be durable.
A few things worth noting: the City has ENORMOUS trunk capacity. The manual one works well on CNG. The suspension is hard. That means loss of comfort but greater control and better handling. If you live somewhere with bad roads, you're gonna hate it. If you live somewhere with smooth textured curvy roads, you're gonna love it.
Best of luck with the decision