I have driven most cars you have mentioned here (except the zest) and own 3 of them in our family,and here are my humble opinions :
I will compare the 1.2 litre petrols here...
Hyundai i20
The kappa petrol which feels sprightly in i10/Grand i10 does feel a bit labored in i20. also the 1st two ratios in elite i20 are shorter to allow peppier getaways I think. Dont go by the ARAI numbers . We have a petrol i20 (nex-gen, the one with DRL) and it struggles to give mileage above 10.
Hyundai do have the most refined 1.2 petrol here imho, though not the most powerful. Esp in the i20 , you step on the accelerator and the response is muted. But enough for the city chores. Did I say it is ultra refined. Oh and it is most spacious of the three hatchbacks we have (Vista is even roomier)
Polo
Although the polo is as wide as an i20, the rear legroom is very very poor.
The 1.2 litre engine is noisy and gives a crude sound when pushed. However two areas where the polo does score over the i20 petrol is driveability (feels peppier) and fuel economy( maybe because of the 3 cylinder engine?)
And please dont say the VAG group cars dont rattle beacuse of the superior build quality. Our 4 month old polo rattles from atleast 4 places. There are similar threads about the same in team bhp regarding the new polo/rapid/vento models.
I bought the polo because I just liked how she looked and I was afraid VW will change the look in 2015/2016. And I always had the ritz to drive when I wanted a change
Maruti
They have the best 1.2 petrol engine in the market. The new swift/ritz come with slightly detuned engines but it is still a holy smoker . We were lucky to purchase our ritz in 2010 and it came with then newly introduced KB series engine. The car has done 30k kms, and driving it (esp after driving the polo/i20) is like having a nitrous strapped to your back. It is not as fuel efficient as the polo petrol, and the handling,braking is subpar., but still if you are an engine man, look no further then the swift/ritz petrol.
of the three cars we have, the polo returns 14, ritz 12 and i20 9-11, All with Ac, All in a tier 2 city but no B2B traffic. The Ritz can deliver more, but I think the engine makes you go heavy footed.
I would suggest you a grand i10 Asta(o) petrol or a swift/Ritz Zxi .
Have you considered a Figo titanium diesel?
I personally dont like how sub 4 meter sedans look. I think they look like ladies who are crossing the road with their skirts raised to avoid getting wet.
, no offence to any owners.