Regarding the fuel consumption, it gets much better with some more mile on it. Mine (1.2 dsi liter gas engine) uses about 3.4 to 4 liters per 100 kms at cruising speeds of 60 mph.
There has been some issues with engine management on early Jazz, which lead to poor performance and excessive consumption. Those have been sorted out by now.
My wife has had a Jazz for a couple of months now and is over the moon she can easily average 50+ mpg locally with up to 60mpg on run. The light clutch and beautiful 5 speed box are a joy to use. One tip to those not getting expected mpg, although the brakes are very effective, try not to use them!! remember every time you use the brakes you are wasting petrol in the form of warming up the brake disc. think ahead and avoid heavy braking and your mpg will soar.
An update on my original post. Our Jazz is now loosening up nicely - fuel economy has improved (or maybe our driving has adjusted to the car) and now averages 42mpg. The car is used in London, so 42mpg is quite impressive.
The car continues to be fault free, and attracts a lot of positive comments from friends and family for the quality and space of the interior.
To answer the questions from the chap from Hong Kong: the car pulls extremely well and should cope with all, but the most extreme of hills. The car has a 4 star safety rating in Europe (NCAP) - not as good as the latest cars from the likes of Renault or Toyota, but still a safe car.
I've done a lot of research on my next car (about to change from an 01 Vauxhall Corsa) and have just ordered a Honda Jazz as a company / lease car - I found your comments very useful. I've gone for the 1.4 DSi CVT-7 SE. I wanted a small automatic that wouldn't guzzle fuel, was flexible and got four people inside in comfort, instead of the relatively cramped Corsa. I'll post comments on how I get on.
Honda lent me a Jazz as an courtesy car while my Integra type R was having some major work done. Have to say I was impressed, it's not as quick and I wouldn't want to blast down a B-road in it, but as a city car it was fab. Definitely would consider one in the future if I ever need something more practical.