this is how I use rayswitch.. maybe this isn't the perfect way, anyway..

first of all this is my test scene:


and this is the materials for the sphere and the plane:


then, in the hypershade, I've created a new rayswitch node and a mia_lookup_sperical (into this node, in the texture value, i've opened my HDR environment image):


now.. the rayswitch node have multiple inputs:


EYE is for what you whant so see in the environment of the camera (like an imageplane.. or an IBL standard setup)

ENVIRONMENT is what you see in the reflection of the materials

FINALGATHER is what FG needs to illuminate your scene with your HDR image (in this channel, for a better FG result, you can blur your HDR, and reduce the image dimension to a 1/3 of the original)

this is the result with environment connected but eye and FG not connected


this with eye and environment:


this with eye, environment and FG:


hope this can help you.. and apologize for my really strange english ^_^