Nice post, Matt (well, posts - this and your other post-blackout posts) <img src="images/graemlins/grin.gif" alt="" />
The M6 has very good word of mouth on the Candlepowerforums web site (I don't own a Pelican M6, but I'm considering it).
As far as the tailcap not having a clickable on/off switch, I've heard of two solutions. One is to replace it with a SureFire Z49 tailcap (I believe this is the higher-end, higher-dollar solution).
You can also use an aftermarket clickie tailcap from flashlightlens.com. This is apparently pretty popular, but at least one problem with this choice is discussed in this thread:
Clickie problems And finally, another popular way to use these is to swap in an LED module. On the candlepowerforums site, a search for "McModule" will bring you to some threads that discuss these high-power units.
These are made by some very skilled fellows who collaborated on the design and manufacture - but they are not a flashlight company, just dedicated modders.
They are occasionally available in small batches either from the original makers, or occasionally a used one comes up on the buy/sell/trade portion of the forum.
I have not seen one of these, but the light output is said to be very impressive, although *I think* they don't "throw" quite as far as the original lamp does. Also, these are expensive - generally, about double the price of the original flashlight for the McModule alone.
That said, they are prized by many on the site.
I hope this helps.
Dave