I bought a Ph2 172 last month and in the past had a 16V and Williams. £7,800 got me a very smart 02 example with 19k miles on the clock - I bought privately from a local Cliosport member.
I was also considering a brand new 182, 172 Cup and Ph1 172 (in that price order). In the end, the Ph2 172 best balanced value for money and equipment.
I drive fairly economically for the greater part, but do thrash it now and again. Over the last 500 miles, the 172 has averaged 34mpg. I think thats pretty good - especially when my last car (Fiat Coupe 20V Turbo) was doing well under 25mpg on average. Id say that £20 takes me about 200 miles.
There arent many common faults - just "niggles". Ive had to have a quick shuffle around the airbag wires under the passenger seat and the exhaust is a bit buzzy (despite already being done under warranty), but these are minor quibbles and dont detract much from the ownership experience.
My humble opinion is that the 172/182 are excellent day-to-day hot hatches and balance B-road thrills with practicality better than any other car I can think of. Driving mine doesnt quite have the sense of occasion as my old Williams, but the more subtle appeal means that the hot hatch Clio has kind of grown up with me - and its defiitely long-term material.