I would not suggest swift for buying at this moment just because it is just about 2 months or so when in Auto Expo Delhi MSIL will give a revamp to its go-cart hatch baby.
Instead I would suggest you to look for either Ignis/KUV or TATA TIGOR. Personally I would prefer TIGOR as it gives you a bit more space and value for money for every penny that you spend. + it is a compact sedan and loaded with lots of good features and it is not hard to get good discounts and offers from TATA motors dealers these days.
you confusion is right and I would like to add a bit more. Look at new Rapid Top Spec diesel with 7 speed DSG auto box. It comes with Sports mode and give you features like TCS, ABS, Dual BA, Hill Assist, Auto headlamps, Rain sensing wipers and a gear box worth spending for + there are excellent offers going on at this moment.
Overall Nexon scores on fresh looks, better in-cabin space and a well planned interior, whereas Ecosports scores on Tried and Tested, Good driving dynamic and better resale value however keep in mind Nexon and EcoScports both have a new power plant in the heart and so the reliability of these engines should be given equal points.
I would suggest check both of them side by side. What it means is test drive them back to back and then decide.
Go for City CVT as it is best suitable for the city drive with the ease of automatic transmission and technologically a better option than VW/Skoda Petrol automatics. VW/Skoda do not offer DSG in Vento/Rapid pertrol and instead they have conventional auto box which are matted to 6 speed gears whereas DSG is 7 speed.
So go for City if you have petrol in the head.