Just remember the Jazz is on the (wait for it) City platform, and is a world car. The City and Etios are cost engineered for the economy markets. Also, I will be surprised if in real time Etios can match the economy of the Jazz. Toyota engines are good, but Honda are in a world of their own.
I faced the Honda v Toyota dilemma in 2010 when I bought the Civic. I zeroed it down to Altis for Manual and Civic for AT. Then it turned out that the Toyota dealer was unaware of the impending BS-IV. As it happened the RSM of Honda Corporate, a Mr Negi, wanted to fob me off with a BS-IV compatible car, which I objected to, and so had to wait another month. All this was March 2010. I got my car on 1 July 2010 - the day of the launch.