No comparison at all between the Fiat 500 and the CT. The 500 is WAY smaller and much more downmarket. Whilst I could get away with using the CT as my main family car (wife and 2 daughters, all under 5'2"), there's no way I could consider doing this with a Fiat 500.
There are loads on the road here in the UK. Don't get me wrong, they are great little cars, but it's like comparing chalk and cheese.
Agree that Top Gear would ridicule the CT as too slow (This week's show ridiculed an Aston as it was optimized to go round the Nurnburgring, they said the ride should be softer)