I went from 172 (several actually) to a CTR to an 05 WRX PPP and can recommend them all, but all for different reasons. Certainly none of them are s**t as some people seem to think.
The CTR was more reliable than the Clio, didn't seem to suffer from the constant stream of niggly annoying problems that the Clio did (airbag lights, knocking suspension, exhausts rotting through every 12k, rattles etc etc). CTR had similar fuel consumption to the Clio, the WRX has depressingly worse than both.
The Clio and the CTR were both more 'chuckable' (as someone said!) than the WRX is, but the WRX does make you feel like a rally god through country roads
Oh, and it feels more on a par with the Honda than the Clio build wise, is much quieter and both and sounds fantastic without being too in your face with the Prodrive exhaust.
And finally, on the MG ZS argument, I had one of those before the 172 and loved it. More reliable than the Clio, handling every bit as good, engine sounded much better and great fun to drive. Almost identical performance all round imho...
But which to get....if you want a hot hatch, go for the CTR (sorry Clio people
) and if you want a 4WD turbo saloon and can afford the extra running costs of an Impreza, you won't be disappointed. They do have a completely different feel to drive than a hot hatch though so it'd be mad to decide without thorough test drives of all.