Hello Anuj welcome to TAI
. Well you drive a Palio? Then don't ever think of i20! You will feel terribly disappointed with the boat like handling and lack of steering feedback from the car. But if you have taken a TD and have decided to adjust with it then as others said do wait for the facelift i20. But as far as your queries go AFAIK
i20 does not have any suspension issues , just that its tuned for comfort and so at high speeds the car is not very stable. As far as AC goes yes during summers the cabin takes a LOT of time to cool. And as far as the steering rattle goes not all the cars have that issues , only few have them. All the above are based on the fact that my friend owns an i20 Asta for 1.5 years now.
But since you already have a Fiat why not Punto? You will feel at home!