I know there's a lot of controversy about them. I don't know if it actually "helps" him in any way, but I do know he seems to enjoy the light and will sit directly under it, especially in the winter when it is overcast and rainy out. We actually have no other lights in our living room (no joke) and Kiwi is towards the back of the room. Place is designed to allow natural lighting through the large skylights and windows, large fluorescent light fixture in the kitchen provides light at night (we are actually looking into designing a solar powered LED lighting system for the living room, but are still researching on how to do so). We have been using the featherbrite lamp for a couple years now for a couple hours a day. We plan to put it on a timer since the on/off switch for the light fixture we plan to use now will be difficult to access behind that big shower curtain behind the cage.
The fixture from Featherbrite was designed to sit directly on top of the cage (boy was bird proofing the cord on that "fun"!), so it was right on top of him. The fixture we plan to use now used to hang above my bearded dragon's tank and had actual heat producing super high wattage bulbs in it for years (actually had a professional electrician wire it to handle high wattage bulbs and it is made out of glass and iron), so the comparatively small amount of heat the featherbrite bulb puts off should be no problem at all for the fixture. Kiwi is not flighted and I don't foresee any way he could ever access a hanging fixture, much less a domed one with nothing to grip onto.
3' feet (just a little down from the ceiling) sounds about what I was thinking, but wanted to be sure it would be close enough for him to still enjoy his bulb