I love this shield questions 
Let's calculate a bit here:
In 10 incoming attacks an - 5/20 shield will trigger on average 2 times leading to an 10 dmg reduction. Also a Chance of triggering 0 but also a chance of triggering 4 times to only break even on a - 2 version so u need at least 5 procs on 10 Hits to get on the level of a - 2. Wich is more then TWICE then the avergage. This is pure risk. And PvP mode is all about reducing risks.
An - 2 shield will get on 10 hits get an 20 dmg reduction. Safe. Allways. Plain and simple. No risk. Just reward.
But at the end it's a gamble with the - 5/20 and the - 2 is ALLWAYS there for you.
Guarennteed > gamble
Because I can hear the haters allrdy "uuuuh 10 attacks is not enough to take evidence bruuuh"
We can take a step further:
Let's pretend a - 5/20 is better then a - 2: With that logic a - 5/20 shield+ demon for a DoA tanks (who take 100s attacks on a big ball) would be worth more then a - 2? Do sales prices follow that logic? No for a simple reason
-2>-5/20
And now let's spice things up to the moon!
Only "Advantage" of a - 5/20 is that it's uncond
BUT:
If u are playing GW on any higher form or level and don't use stances or Enchantments in your build then you should really consider to overthink everything you have done so far 😜
well made.
