I had the same dilemma.
I bought Fiesta ZXI Petrol. Very happy with it. you will also get great pricing for the same.
Aveo is not so powerful but has great interiors. LS version doesn't have anything and you need to buy the LT at least. Secondly, you will have A.SS issues as well as resale value will be zilch.
I do not disagree Aveo is a good buy. But I think it is bit old model and we have Linea and Manza really doing well. Guys, it is really worth considering these two.
Aveo has two version 1.4 & 1.6. Naturally there is differences but a car is popular by its onroad maintainance and how u feel driving. In India there is not so much cars and buyers to discuss with it. I saw it for years on road and then gave my experiences only. I have driven Fiesta also.....Dr. S.K.joshi