Single Agent Developers: Metol vs Glycin

I've read of Glycin being no more than a high ph Metol.
As a single agent glycin's operating ph is usually provided
by a carbonate, films, or for papers trisodium phosphate.

What though is glycin's reducing potential? Glancing over
developer formulas I'm left with the impression that it takes
a few times as much glycin to equal metol's reducing power.

At twice + more expense than metol and perhaps needing
double or triple the amount it would make for expensive
processing. Gram for gram how does it compare? Dan

Since glycin is rarely used alone; and since it has features other than mere reduction, such direct comparisons are difficult to make.

Ansco 130 lasts quite awhile, maybe that makes glycin worth the extra expense.

Glycin developers are indeed very long lived. I haven't seen any evidence glycin does things other developers can't do when it comes to actual development, but the shelf life of the stock solutions and the working solutions is outstanding, far better than any non-glycin developers I've used.

Single agent developers GSD-10 (glycin) and Beutler (metol) seem to give about the same development time with glycin 2g/l(pan F example) and metol 1g/L if agitated on the minute.The other ingredients sulfite and carbonate are in similar concentrations.This info from http://gsd-10.blogspot.com and the massive development chart though there is no exactly comparable data.

Alan Johnson said:

Single agent developers GSD-10 (glycin) and Beutler (metol)
seem to give about the same development time with glycin 2g/l
(pan F example) and metol 1g/L if agitated on the minute.
The other ingredients sulfite and carbonate are in similar
concentrations.
This info from http://gsd-10.blogspot.com and the
massive development chart though there is no exactly
comparable data.

Click to expand...

So, twice the expense per gram and twice as much needed
makes glycine four times more expensive. That's out of the
bottle and does not take other factors into account. For
example, I've metol going on eight years old and
still working very well. On that basis alone
metol is an even better value.

Many who use glycin swear to it's longevity in solution;
stock or working strength. But metol, although not having
an equal reputation for long solution life, does have good
keeping qualities. Dry and in a well sealed bottle mine,
on the shelf, may be as new ten years from now.

Glyin must have something going for it besides long
solution life. Forget it's long solution life. What does
it offer film or paper that metol does not. Dan

Glycin was popular as a stand developer in the early 20th century (film developing Cookbook p37) as it is less likely to produce streaking.It may have been introduced by A Hubl (1897).
For normal development it gives clean fog-free negatives but works better with a little metol added to increase its threshold energy (BJP 1945 p189)ie,not as a single agent developer.In this form it was popularised as FX-2 by Crawley.

In my terribly minimal experience (FX-2 and Ansco-130) I do notice more shadow detail in a series of tests I ran w Imagelink. Could be it's softer working than metol, even?
What's its history? Was it before or after metol? If before, then I could easily believe it fell from favour for the 'new' and 'better' agent. If after, cost could have been the the deciding factor, as you point out.
Murray