In some states it's illegal to dispose of them in a landfill, of course that doesn't mean people won't do it anyway. On the plus side, there's such a minute amount of mercury in them, and landfills are now built so carefully, that it's unlikely that it will ever leech into water sources.
CFL's were never intended to be exceptionally bright. They're meant for an energy-efficient replacement for incandescent lighting, and do a good job of that.
So far there is only one way to save money on evergy by switching to fluorescent over any HID lighting, and that's to reduce the amount of light.