Cool, like a dimmer with presets! I kinda like that idea!
Yep, though I think they're a bit more trouble than they're worth. We generally lose the 150 watt filament rather quickly, and then we're not sure whether the lamp is actually off, or just on the 150 watt setting.
Most of the lamps around here are made for 3 way bulbs. Quite honestly, I only use one setting (when it's not burned out), so it's a waste for me, but others may have different opinions.