We will travel through Wales, England and Spain this summer, arriving at Gatwick airport. I plan to buy a chip for my ipad mini when I get there. Any advice on whether to buy a chip at the airport vs. a city phone store? I've had some poor past experiences with both scenarios in the past and can wait till we get to Cardiff. If anyone can make a specific vendor recommendation, please do.
Also, is it still necessary to buy separate chips for Britain and Spain, or is there uniformity of service across Europe now? I'd read last year that the different countries were trying to become more "user friendly". That would be nice!