Financially it'll be a terrific move for him, and as Edna says, he has the spine of a squad there where there's certainly something to build on. It was a no-brainer. Stoke are a far bigger club than Luton with much more potential. He'd have been nuts to turn this opportunity down.
He probably had a lot of TIME in the bank at Luton, but you can be sure that he'll certainly end up with more credit in the bank at Stoke - and certainly if they bin him off. Thats going to be a huge factor for him, as he's unlikely to have been on decent money (in footballing terms) throughout...