I have the 1.2 i-DSi and I love it. It is an incredibly flexible wee engine. On a flat road it will pull from 25 mph in 5th and just an hour ago I was driving on a flat road, in 5th, at 30 mph, with a cold engine, and my ScanGauge was indicating 68 mpg! I have never had problems with a hill start, anywhere, and there are plenty steep hills here in Scotland.
I opted for the 1.2 for the slightly cheaper Excise duty. I have owned it for almost two years, maintenance has not been a problem and the figure beside my avatar shows the average mpg over that time. Most of my journeys are short trips, in town, engine cold, as I take my wife to and pick her up from work. I normally sit around 60 on motorways, but it will do 70 with no stress. I find the loudest thing at those speeds is tyre noise.
Listen carefully to the gearbox on any car you go to look at. With engine running and in neutral there should be no difference in noise between clutch up or down. If it is noisy with the clutch up the input bearings are shot. I just had my gearbox rebuilt, but it cost £324, so be aware.