people buy them cause they're 'sexy'. good reason to avoid if you ask me. my ex missus had one from new(petrol)
new engine after 30k, although with arm twisting alfa paid 80%.just outside of warranty.
Focus are great although fords have never been great for diesel engines unlike the french who make v.good diesels.they are generelly complicated though, my sister in law flattened her battery by leaving on the lights overnight and had to call out renault (megane) to open it, reset the computer and supply a new battery.350euro.
nissan , honda and toyota don't make anything that isn't good, petrol or diesel.
finally diesels are not what they used to be and they do get you moving.