This is a hard question to answer, because any comparison of graphics API's will inevitably depend on the drivers you are using, the operating system, etc. However, OpenGL and OpenGL ES are very similar (who would have guessed?), but in many cases are mutually exclusive. Mobile systems don't really support "regular" OpenGL, so your only option is OpenGL ES. Some desktop vendors only support OpenGL (like Intel, I believe), whereas others support both GL and GLES (Nvidia). You'd have to talk to one of the driver developers to be sure, but my suspicion is that a huge chunk of the driver code is shared between GL and GLES, if both are supported. There is not likely to be any performance difference, because the API's are so similar.
On another front: OpenGL ES is missing a lot of modern features that "regular" OpenGL has, and many of those modern features are aimed at performance. For example, modern OpenGL ES still doesn't support direct state access, which is a handy extension for avoiding pointless bind/unbind calls. Since it's missing some of those performance-centric features, OpenGL ES should be a little bit slower, all other things being equal. If you stick to the stuff that is more-or-less identical between GL and GLES, then I would be surprised to see a difference on the same hardware.