Basis bhai, nice thead but I'm not sure whether it belong to Indian Auto news section. Anyway, let Mod take it own course :).
On the basis of 9 month experience, following is my observations about Honda Jazz as per your set points:
1> build quality : 8/10
2> engine :8/10. Disappointing low end is a minus factor.
3> long term maintain cost : In my first paid service I shell out 3.5k.
4> mileage : 8/10.
Even during spirited run with full A/c, Jazz gives more than 14kmpl.
5> drive / ride quality: 7/10.
Handling at the corner is susceptible (body roll creeps in) and ride quality at low speed is harsh.
6> comfort :10/10
7>boot space: 10/10
9> spare part cost: 8/10
10> looks: highly subjective 7.5/10
So do I consider it the overall best petrol hatch? Yes. Since new Swift has minuscule boot space and weak brakes (except for top model), so I still consider Jazz to the best petrol hatch.
For diesel, new Punto 90 HP is probably the best overall hatch.
i20 has a gem of engine but whats the use of power if you can not use it (due to boatlike handling).