Hey Qwe2,
I had the focus ST diesel for 6 yr before the jcw. I had the same reservations as you. But the JCW is so much fun, much more so than diesel hot hatches. Well worth the extra fuel cost. So far the increase in cost is minimal. But I am taking it easy atm.
I found the space upfront greater than in the focus.
If you do not need the back seats then keep them down and you get more space than a standard hatch boot with the seats up.
go for a long test drive and try not to smile. I bet you can’t. It’s the best car I’ve had,
a proper little rocket. ??
good luck finding your new car