having had all 3.
VXR......worse on fuel than cupra. Average high 20's MPG, terrible...and i mean terrible torque stear. Far too light on the back end...same problems as the old Mk2 Astra GTE.....if you go that far back. Nice looking car...but inside feels cheap and stereo is RUBBISH.
Focus ST- worse on fuel than cupra...low 20's MPG. Very nice to drive....sounds loveely when you open it up. Well balanced....feels more like a large engined BMW in power delivery. Probably my favourite out of the 3....but fuel consumption makes is a pig. And...of course...theres the image. Also...its due for replacment next year. So residuals will drop.
Cupra- Low 30's MPG as an average. Nice shape...drives very well far better than the VXR, not as good as the ST....can be a little un involvling at times, interior on facelift is noticably better that the older ones. 5 door practicality and most will assume its a 3 door. Rare-ish. Oh...and facelifted ones sound alot nicer than the older ones too. Think they played with the airbox/exhaust accoustics a little.
Hope that helps?