I've had my Windows computer for like five years and it still works about as well as the day I purchased it, as far as I can tell. My iPad of a similar vintage is not really that good for surfing the Web anymore (though to be fair I think we can probably blame the explosion of complexity of Web pages) and I can't seem to make any purchases in the App Store anymore. I think it's hard to make much judgment here without more serious data than one or two people's experiences.