My E2e does have a "clicky" tailcap. I have found it rather easy to activate even with it being locked out.
The holder that I have my G2 in is a Perfect Fit Inc leather holster with a snap top and no bottom. It does not turn on when I sit down. But I did notice that while taking it out a few times tonight, it does not come out as easy as the Strion did. Possibly this is because the grip has more grooves in it on the G2 than the Strion.
I went on the Blackhawk website and was unable to find the CQC holder that you are referring to. I would need one that rides by itself. I would prefer flat black to carbon fiber.