I am telling you that Glyph of AMS is mathematically no better than un-glyphed AMS unless you will die during its duration. If not it absorbs the same damage. Lets say AMS absorbs 100k (after battle fatigue) and you take two ice lances for 75k each, 150k in two globals.
With Glyph of AMS:
GCD 1: 75k absorbed.
GCD 2: 25k absorbed, 50k damage.
Final result: 50k damage taken.
Without Glyph of AMS
GCD 1: 56.25k absorbed, 18.75k damage
GCD 2: 43.75k absorbsed, 31.25k damage
Final result: 50k damage taken.
If you would have died in the first GCD, and the extra one GCD would have saved you then Glyph of AMS was worth it, otherwise it was a waste of a glyph slot. If you're waiting until you are below 20k hp to use AMS then I think you need to reconsider your play style. Frankly DK's have many 'good' glyphs. Regen magic, dark sim, IT, shifting presences, dnd, and even unholy frenzy has its uses, but Glyph of AMS almost never makes sense. You're sacrificing glyphs that have clear general purpose worth for something that will help you less than 1% of the time.
My point in the second paragraph is that you shouldn't just drop names or follow what high rated players do to back up your argument if you don't know why they do it. Saying "Katsuora/Mes does X," isn't an argument, but saying "Katsuora/Mes does X because ..." is. If you can't provide the second one then don't mention them at all. I'm sure Katsuora has his reasons for glyphing AMS on what I assume is his second DK (maybe it's some impostor?), but I have no idea what that is, you don't seem to either, and it could be due to something completely random (i.e. desperation, pve, duels, or whatever).
I'm not telling you to listen to me, but I am telling you to re-examine your reasoning because it, frankly, isn't good enough to justify using the glyph. Also don't just blindly follow what better players than both of us do without knowing why. Good players do random things, they do bad things and often they experiment. However more often than not their situation isn't the same as yours so you should take what they do with a grain of salt.
I already told you I never glyphed AMS because some other DK's do so drop that argument, the only reason I even linked other DK's who use the glyph is because I am only 2250 at the moment and so some retards will use that as leverage to try and argue something as stupid as thats why I am not higher. Infact it doesnt matter about the third glyph thats the truth there is actually only 1 glyph that I would say is needed, and that is IT. stop pretending like its such a bad idea to go AMS when it clearly isnt, I looked over the 3v3 ladder and there are plenty more DK's there using it so its not because they are dueling or whatever excuse you care to make up, that seems very unlikely. The bottom line as i said earlier in this thread.
I use AMS almost exclusively at low health unless i think Im getting CS'd at which point i will use it more at around 40%. Im not going to AMS because the mage looked at me, he will simply thank me and wait.
The way i play is i use AMS late I play a human so I have a free trinket so CS doesn't bone me as much as it can bone others who play without one. lets say for example im not even facing a wizardcleave, which is obviously the best situation to use the glyph lets say im facing WMD, I can be on low hp and stop the warrior doing damage to me, I could kite him with chains i could pet stun him i could asphix him, but no matter what I do to the mage he WILL get a few lances off, what i take from the glyph, and try to understand this because its important, is in that slot I have a few choices for a glyph, I already use IT and shifting presences, I could take regen AMS glyph, well i actually do that vs teams without any casters so I can sit on priests and shamans, but most teams have a caster, I could take IBF but i actually like that it lasts 12 seconds unglyphed. I could take dark sim but ive already explained all this twice before. I dont take AMS because I think its an amazing glyph
I take it because actually that situational survival that it gives me is better to me, and obviously some others
than the other options available, stop pretending Im trying to argue taking this glyph over IT or SP because im not. Nor do i think taking AMS glyph is needed, im simply telling you that it has saved me, it allows me to rely on AMS in a way i cannot without the glyph and that is the reason i take it as my third inplace of other options.
Also AMS absorbs 165k unbuffed with battle fatigue so its actually 3 seconds of immunity to damage from those icelances rather than 1. so its 'only worth it if you would have died in 3 seconds' which actually yes can happen, again not often and again IT ISNT GREAT but its a better choice from my perspective than the others.
Anyways im going to sleep now and bored of this because its actually such a meaningless discussion I guess some people will use it and some others will not but ultimately its not as important as IT and glyphing AMS does not make good dk's bad nor does it make bad dk's good its simply a choice and probably one of the least important ones you can make on your DK provided you nailed the other 2 glyph slots.