>BTW, i presume you mean the ones that take a wee while to actually come on, and that don't yield all their light straight away - a bit dim but then, imperceptibly get up to their working brightness.

A friend of mine installed only those, such as were available, in his toilet back in 1991. They took 2-3 seconds to come up. The tiles were brown and the porcelain was caramel color, so you couldn't really aim under the bits of street light that may sneak in... at some crucial moments it was almost a proof of the relativity of time. Those two seconds must have stretched significantly.