I drove Suzuki alto 660cc vxr for 4000 km now. i have found out couple of good and "bad" points in it which might interest you.
Mileage to me is currently 20.6 with AC (i am from Lahore and daily use ring road to commute for office) in city it would be around 18 to 19 with AC at max.
I went to kalar kahar with my wife and tow kids at 90 to 95 speed through motorway whole trip back to Lahore cost me 2400 rs average was 22.4 km/L. so undoubtedly mileage is great.
Front two seats are extremely comfortable as compare to wagon r.
AC is good not great but you are can live with it.
handling is good but power staring get stiff some how no idea why.
every thing changed when you put 4 adults with 2 kids in it. you feel car under power, Ac still works, handling sucks, you feel road very rigid as treys are thin.
one big bus on highway or on motorway can move your car like crazy.
All in all its a OK car. can serve your purpose to commute but make sure you are not adding more weight and never over speed and expect same performance.