Well, it does work perfectly fine as far as I'm concerned and it has a better tactile feel and no more wobble or scraping between the tail cap and the metal boot.
Regarding waterproofing, I don't think that is the case any longer, as the metal ring sits on the metal (well.. aluminum) tail cap with no seal. I'd say, gluing the metal ring on the tail cap would bring back at least water resistance through.
Regarding accidental activation, it's a bit more recessed, thus more reliant, to say it like that, but I still wouldn't bet my nuts on it in every instance, say.. having stuff in your pockets other than the light itself.. or having it in a backpack (although, having it in a backpack wouldn't really be a situation where you would have a good reason to keep a light unlocked and ready to.. fire)
Cheers!