well i couldn't just read this thread and not comment. although the new innova's look like a very good product, they use expensive lithium batteries and are not regulated. this means while they start off about as bright as an arc ls, they get dim very quickly. teh opalec newbeam keeps an absolutely horizontal brightness curve over time (until the end) and has a tiny red led that lets you know when the batteries are depleted. it also uses common double a's. the innova does have a tactical switch on the back for momentary illumination and if you have lots of surefires it can be used to squeeze teh lasts out of the 123a batteries. so if consistent bright light is important to you you might be better off with the albeit more expensive newbeam. if you just want the cool factor of the x5 than you might be better off with it. you can find tons of threads on both of these lights using the search feature on cpf, so you might do some research. also, i think the blackening is caused by carbon molecules ending up on the inside of the glass, but i'm not sure about that. hope this has helped more than it has confused.
- Pete
