We had our Citroen C8 from new in 2004 until about six months ago. It was great for about four years and gave us little trouble, but then started to have more and more problems, and then the gear box went at 65k miles and that pushed us to sell up.
If you get a C8 with less mileage I'd still say go for it. Ours was extremely practical for family use, very easy to get into all the spaces inside, made easier by the lovely big sliding doors. It's really cosy and comfy for long trips or just weekly shopping type trips. I suppose it's worth pointing out that the sixth and seventh seats in the very back are really just child seats, but that's to be expected really, I haven't found a people carrier with seats all that big in the boot. There are these little flip up tables for the back seats which are handy but can be a bit more hassle than they're worth because the lip round the edge isn't very good and things fall off quite easily, and then obviously get lost under the seats. There's masses of space round the Citroen C8 for storing things though, so not too much stuff gets left on the floor. As for the boot, well with all the seats up you'll get a pram in there and the baby gear, but not that much else. There's lots of space in the car for things though, so that's not too bad.
It's really quite good for petrol use, we'd got about 45mpg on motorway journeys. My husband complains sometimes that it's not quite the sports car of his dreams, and I suppose it does take a while to overtake and things, but really it's fine. The driving position in the C8 is great too, lovely and high up and very easy to see all around, plus the sensors for parking help to show you in and out of spaces, most practical indeed. It can get a little bit noisy on the motorway but really not that bad, and the stereo also adjusts itself when the noise gets up which is really clever.
The repairs started about three years ago now. First of all the handbrake failed one night, which we only realised in the morning. Fortunately we had it pointing into the kerb otherwise it could have been a great deal worse. We had the fan belt go which the garage blamed on some sort of leak inside. Various lights kept coming on suggesting different faults, but they all turned out to just be the car's overactive imagination. There was nothing actually wrong, so we were just spending money investigating nothing. In the end we started to just ignore the lights and do our own regular checks on the fluids and things, which was pretty tiring really, especially when you've got kids messing about! The inside generally got very old towards the end too, which is to be expected with kids tearing chunks out of it all the time. Still it certainly looked ragged by the time we sold it.
We've ended up getting a good deal on a Range Rover to replace the Citroen C8. It just seems a more reliable car for transporting our flock in.