Generally, very impressed. The Clio is a small car, with a big car feel. Ideal for the first car.
Interior on the Expression - generally good quality and a nice bright feel - unlike some of the other interiors in the range (such as the Authentique and Dynamique, despite the latter being the top of the range model).
Engine is well designed and offers good performance for its size. Service intervals are well spaced - ideal for keeping costs down.
Air Conditioning works well. Definitely recommended if you can find a Clio with AC.
Generally a good driving position, and all controls are easily reached and are easy to use. Stereo on the Expression can be controlled by a steering wheel "satellite" - controls just behind the wheel.
Power steering on the 1.2 16v engine is electronic - powered by an electronic motor rather than a hydraulic pump; meaning no power steering fluid to top up; and the system doesn't take power from the engine (ideal for parking, etc).
I genuinely enjoy driving the Clio. I have not had to do anything with the car except have it serviced (recommend - ask for Fully Synthetic engine oil if you have the car serviced by an independent garage).
I have heard of these cars being plagued with engine problems - several friends have these - just check the log book, and try and go for a car with "1 lady owner".
The Clio really doesn't deserve all the bad press - it's a great little car, and I'd recommend one to anyone.