Keep in mind there are all sorts of LEDs.
The ones in the Glo Toobs are smaller and not super powerful, and reflected off an internal surface.
Also note the Mini Flasher as referenced above, also has a wimpy LED (and only one -- less than the Glo Toobs).
While I like and have some of the 'Toobs, the new LEDs like in the Fenix P1D Q5 are HUGELY brighter.
In reality, it would be interesting if Glo Toob re-spun the 'Toob with a modern, high-output LED.
The Glo Toobs don't float.
Also note there is now a lithium powered (123A) Glo Toob which probably has much better runtime than the old FX model.
Some Glo Toob pics.
My guess is that a Xenon strobe would beat a Glo Toob easily, regardless of visible or IR.
Bottom line is the Glo Toob is a marker light, not a rescue beacon. Ditto the Mini Flasher (actually, I'd consider the Mini Flasher more of a novelty than a real marker light).
-john
EDIT: BTW Joy, if you are interested in headlamps, check out the Zebralight H30-Q5. Sturdy, three output levels, bright, small/light and it has a great flood light which is great for task lighting.
H30 Review.
FWIW, (in general) I haven't found that Petzl takes waterpoofing too seriously. The Duo LED is also a pretty old design, and personally I wouldn't put it on a short list.
While I don't know about their newer designs, the Princeton Tech Yukon HL does a better job waterproofing than the Petzl, but it is a pretty dated model.
Also note, in general it is a lot harder to seal the battery compartments on lights like this vs the Zebralight style. Zebralight got it right. Less is more.
Another good alternative (although expensive) is the
StenLight S7.
Review.