You guys - thanks for good fdbk here. Peter, you are a nut. Funny but true how much the psych aspect influences everything!

I have recently been paying attention to rope weights and characteristics, and yes, it is surprising the differences in weight vs. diameter.

And I think I partially answered my own question recently when I experienced a different climbing line, Safety Pro - 11mm is typically a choice for mechanical ascenders and SRT because friction hitches become less dependable as ropes get smoother and narrower. (Duh, I know, but for years I never used anything BUT 14 strand 1/2", so what did I know?) It makes sense to use a mechanical ascender because who the hell wants to mess about with a "will-it-slip-or-will-it-grip-or-will-it-bind"? situation if you've got a 150' upward trek ahead of you?

Recently I have had the distinct pleasure to purchase and work with 12 strand Safety Pro. It's awesome!! An 11mm tail tied with a simple Blake's is as effective on 1/2" Safety Pro as a VT with 8 or 10mm eye-to-eye is on 14 strand. It slides beautifully and then it locks fast. The thick (by comparison) weave of 12 strand is a perfect match for any garden variety friction hitch. I bet 1/2" 14 strand tail works great on it too.

And, it's light. And, it doesn't stretch too much.

If I follow my heart and eventually open up a rec climbing outdoor "gym" where people can come and experience the pleasure and thrill of tree climbing, it'll be Safety Pro all the way for novice climbers.

So in addition to the points that you all make - better belay, lighter, more compact, prettier(I love aesthetics, can't help it) I have found that one of the reasons why SRT is mentioned in the same breath as 11mm line isn't because the mech ascenders like the narrow line - it's because the narrow line prefers the mech ascenders - you don't want to be constantly re-setting a hitch on smooth narrow lifeline.

And lastly, I'd rather grip the handle of my Petzl texas _style_ rig than a narrow 11mm line. If I grip the line directly I way prefer 1/2' line for my 44 yr old paws.