I spend a lot of time writing with pen and ink - one ink I use is invisible but glows under UV light. It's perfect for encouraging my young cousins to write (secret messages are fun!). Anyway, I needed a black light for a desk lamp so we can use this ink.
The range of the light is excellent, it fills my 12'x12' dining room, and things glow beautifully (well, except for bits of fluff on a black jumper which glow annoyingly).
This light bulb does all I expected of it - I can't fault it. I'm just hoping it has as long a life as these new fangled bulbs are supposed to.