Normally fuel consumption and power go hand in hand, so wishing for more power will get less mpg, lots of people buy the Jazz for its easy access, which means the higher seats. Also a lot of modern cars get wheel bearings failing due to manufacturers looking for lower rolling resistance and fitting lighter duty ball bearings instead of the tried and tested tapered roller bearings they used to fit.
The Jazz is basically designed for city use, although I never thought my 53 plate 1.4 was struggling on a motorway at 70mph. Turning circle is amazing and designed for city life, really miss it when I am taking 2 or 3 bites at a carpark space in my Civic that I could just drive right into in the Jazz, when we are expecting tight parking my wifes Jazz is the car of choice.