My father wants too purchase a TomTom and has decided on a 710 or a 910. I get 10% the £399 and £499 price at work. Theres no major reason why the 910 would be a better buy, but the old guys not short of a couple of quid and I', thinking for the sake of £90 it might be better to 'future' proof the product as much as one can with all this new tech. Also the extras 'might' be handy in the future. So are there any reason's why possibly the 910 isnt a better buy over the 710, possibly HDD over SD etc?