Folks, thanks for the laughs and the advice. Since you didn't all see this as an opportunity to advise me to buy a BlasTech 500.
I shoot both the 21 and the 686 equally well, maybe a bit of an edge to the 686, but I've always shot revolvers a bit better than autos. Just something about me and my hands. What it came down to for me was trying to decide which was a better choice for the hike as a SHTF/personal defense tool. This is the Daniel Boone National Forest in Kentucky. I'm not really wanting a gun in case a bear or snake wants to get me. I'm wanting a gun on teh hike for the same reason I keep one by the bed, and CCW during the day. The whole reason I'm debating this is (1) in my mind, I've always thought of the revolver as a better survival handgun, since you don't needs mags to make it work...just ammo, and (2) Glocks are ugly and indestructable, so I wouldn't worry in the least about banging it around in the woods for a week.
Either way, I'm seriously considering the Safepacker hoster system, which to me seems ideal for an outdoor adventure.
Thanks guys.