Which Miele washing machine?

Dear all

I am about to purchase a new washing machine. Please advise which you think best out of the following 2 options. We are 2 adults and 2 kids, do between 5-7 loads per week.

1) Miele WDD020 £719 from John Lewis but can get £75 cashback so = £644, with 5 year warranty (from Miele)

2) Miele WDB020 £494.10 from John Lewis but only comes with 2 year warranty, so add on £140 for 3 years extra warranty (from John Lewis) = £634.10.

I can’t really see that there is too much difference other than option 1 being 8kg rather than 7kg (though have read on this website that bigger than 6kg = doesn’t get as good a wash due to how the washing falls in the drums.) Any thoughts much appreciated!

Thanks
Hannah