Appreciate this isn't everyone's cup of tea but for T-Mobile customers wanting to upgrade to the 5 this is probably the best deal out there. Tariff has 300m, 500 text, 750MB and a flexible booster. Nothing to pay up front and £31/month.
If you don't like the tariff you could always give T-Mobile a call once you've got it and change to Full Monty or wait for EE and change to their new tariffs for 4G.
Offer only available in CPW stores, pre-orders made now will be available for collection/delivery on friday.
For comparisons sake I put the URL for the new customer equivalent of this deal, is £149.99 up front.