Originally Posted by
AndyCalling EE's figure does not update instantly. It can take up to 2 days to show your usage on the EE app/site. If you use roaming to go outside the UK it can take even longer to show. Datasense is instant as it is in your phone, so the EE figure will lag behind it.
Something else to keep in mind; if you get any non-chargeable data use, such as to the EE web site, Datasense will still count the usage though of course the EE app/web site will not. If you have a deal where you can stream films or music outside of your normal data cap this can be a significant thing.
New feature for data sense in Win10 should be the ability to add sites that don't use data (I'm sure I've seen plans where Facebook and Twitter are free) and apps as well. That would just step up its usefulness for some people.