I really like the Focus TDDi's. Excellent, reliable engines. Tad noisy perhaps, but I have added some sound deadening into the doors and underneath the carpet and quite a few people think it's a petrol now as far as noise is concerned.
The turbo has a very smooth delivery and if you give it the beans and change up around the 3k mark you can make excellent safe progress with it.
I don't think i'd be able to get any lower than 40mpg with mine. On average I get 51mpg and that is with a performance air filter, 205 width tyres and lowered suspension; not to mention the weight of a not-insubstantial driver and stereo install!
I chose it over the TDCi's as they are nowhere near as reliable- they seem to blow injectors very regularly and would cetainly not be as reliable as mine is @ 130k. I would also definitely not recommend an Astra DTI 1.7 as that's what I had before. Huge turbo lag and the fuel pump/ECU are very badly designed.
I do my own servicing on the Focus- the Ford garage is full of monkeys.
The standard velour interior was nice enough- its the Ghia estate, but have replaced this with leather which is more supportive. Stock stereo is rubbish and so are the stock springs- the car rolled a bit too much, especially with the 185/65 tyres.
Plastics inside are durable and cope well with odd scratches and the overall quality is good.
I would recommend a TDDi Focus, not TDCi.