Hello , There is a difference of around 1.20 Lakhs in on road prices of both BALENO Alpha and Brezza ZXI(on road - Delhi) As u said u have a budget of 12.50 L, Surely go with the Brezza. If u are looking for a feature packed compact sized car with a budget of 11 Lakhs in hand , go with BALENO Alpha.
The Baleno’s 1.2 L petrol engine is a gem! It is a free revving engine with minimal vibrations. Answers to your questions- A . As soon as you press the accelerator hard it downshifts to the second or third (depends on your speed) and gives an instant pull. It overtakes well.(checkout my AGS gearbox review) B. All I can say is , The car feels stable at high speeds post 100Kmph.(although there is a bit of bounce on undulations, due to soft suspend setup) C. I haven’t driven the car in hilly regions but I am sure it will perform well.