Depends if a better screen, faster processor, and twice the RAM and storage space is worth £250 to you. Both laptops should feel nice and nippy for basic tasks. The more expensive one will look nicer whilst doing them.
Is it worth paying for the higher spec model: ASUS Vivobook S410UA-EB046T£599 at John Lewis?
A similar price on Amazon https://www.amazon.co.uk/ASUS-S410UA-BV050T-14-inch-Wide-Angle-Display/dp/B0765F36C6 (I *think* it's the same spec . . .) £400 at Box https://www.box.co.uk/S410UA-BV050T-ASUS-VivoBook-S14-S410UA-BV050T_2200471.html (ditto spec)
Doubting the 200 reduction given specs