Buy Handa City for refinement, nice sedan over all but please consider GXI (I think Exi is base variant) which is good one, however If you don't need or can't afford it buy Exi.
For budget of 7 lac. and 2000km per month Logan D makes full sense to buy! Nothing else in sedan segment according to me but since you don't like its looks I am not sure If we can convince you
In hatchback segment its Swift D Vdi any day If you look for good Diesel hatchback.
After driving Santro I do agree about bgearbox of Aveo. Aveo is good sedan infact VFM comfortable sedan in its class but its your call for sure to decide.
Regards,
Ravi.