No they are not compatable Look Keo have more angle than shimano but shimano are firmer fit and wider . its personal choice cost around same.
Keo are lighter than shimano but I had shimano for 4 years before I changed to Keo.
I went from the Shimanos to the Looks and back to the Shimanos. The Shimanos are wider and more stable and have much greater rigidity that the Looks. It was an easy decision to go back.
I'll have to get new cleats then. I'll give the Look keo classics a go but i do like my current Shimanos. Just getting a new bike and thought I'd try something different seeing as they're slightly lighter.