Is the IPHONE 4S worth while on a pay and go sim card?

I'm buying the Iphone 4S on monday… But i DON't want a contract sim… I'm thinking of going on a 3 network sim which for 15 pounds per month gives… 300 MINUTES, 3000 TEXTS… And ALL-YOU-CAN-EAT DATA… Is this worthwhile for the iphone 4S and what is ALL-YOU-CAN-EAT DATA?

answers as soon as possible… Thank you so much!

Get a giffgaff sim.

Yep! All you can eat data means unlimited data allowance