I'm experimenting with this also, and even though I'm using LED lighting, and the wattage is low, I really like the occupancy sensor.
My sensor is in the kitchen... in my house, the kitchen entry is the main entry used, so it's kind of a friendly feeling to come into a dark room and have the lights go on, especially if your hands are full. My sensor is built into a light switch.
Also, I used to have a sensor in the bathroom, because I couldn't get my children to turn the lights off (now that they pay their own bills, they are relentless watt watchers).
However, I really came to like the auto-on / auto-off switch.
I think that occupancy controlled lighting would find far more enthusiastic acceptance if it had a built in adjustable fader function, with a short ramp up and a longer ramp down. Such a feature is not yet being built into light switches but there is
DIY activity on that topic.
It would be just too cool to not have...
Best,
-AC
This one looks to be for incandescent only... PCM faders, where are you?