Focus ST is half the car the Clio is, but twice the weight and twice the fuel bills.
Well built and nice to drive, effortless engine. Depends what you want it for, every car has pros/cons, can't really compare one to a Clio because thet really are two completely different animals to be honest. If you're not fussed about handling or driving particularly hard but you like a bit of grunt when you put your foot down then the ST is a good car. If you like to drive and enjoy trackdays etc., then the Clio p!sses all over the ST.
Horses for courses. You really need to have a drive in one to get your mind around it.
Is fuel really that bad? I dont do track days but like power when its needed