Went through the same dilemma. Was all set to get the Jazz 1.5 A/T. Went for a test drive and saw the Civic 1.8. Was also available for test drive so test drove both back-to-back. Ended spending more for the Civic but totally no regrets. More space, very adequate engine, 8.5 km/li city, 17 highway. And that was 3 years ago. <100k diff in price.

Now I understand its less than 50k diff for top of the line Jazz and base Civic and appreciate your dilemma even more.

Good luck! Faced w/ the same situation now, i'll probably get the Jazz since the new Civic is around the corner.