I've given up on waterproof overshoes a very long time ago. From my experience, they only really work in combination with waterproof overtrousers, which cover them and prevent water coming in from the top. And I do not fancy hauling around waterproof trousers in the summer.
Waterproof socks suffer from the same problem during the rain. When its really chucking down, your socks and shoes will get wet. However, I still do carry a pair of Goretex socks on long rides. Their key use is AFTER the rain, when the shoes are still soaked. Much nicer to ride in wet shoes with Goretex socks, which keep the feet warm and dry, than in normal ones.