Whilst the A380 F is getting rather grubby / worn and the IFE is pretty ropey, it's still a comfy way to travel and the feeling of space and privacy is decent. I'd take that for £400 for sure.
Is it worth it ? No one can give a precise answer on that point
Edit to add, I've just checked and see there's also 781 flying. I'd definitely take that over the other.