we have a 52 reg c5 2.2 hdi estate and it's great. there is bags of space, maximum comfort and it has citroen's legendary suspenstion which has six settings. also, when hitching up, there is a button in the boot to raise and lower the car in case the jockeywheel won't wind down anymore. this is only on the estate version though.
it does everything for you. automatic wipers, self-levelling suspension when you get in and on newer 53 reg onwards some have a rain sensor which puts the windows up automatically.
the 2.2 engine has plenty of pulling power, and it made it up a 1 in 4 hill with the caravan on the back and stopping halfway, in 3rd gear.
now we come onto economy! 40-49 mpg solo and 23-30 mpg towing. the most economical speed solo is 50 mph and if you keep it to that we have had 54 mpg on a motorway.
the new c5 that has just come out has a glass roof and a sensor to measure the length of the parking space you are getting into.
early c5's pre 2003 can run into problems. we have had a few but 004 onwards you should be fine.