Im not in the UK but can relate to it
I too changed from a D5 to an X7, yes its longer but no issues by comparison, as has been mentioned the cameras are really good on the X7. I also find the split tailgate better plus many other positives for me going back to BMW from LR.
I cant comment on the 30d as I have the 40i.
I don't think you will be disappointed with the change.