How many pieces of gear are there, really, that outperform the humble +2 armor and +1 shield?
This means +2 studded leather for light armor, +2 half plate for medium, +2 full plate for heavy.
Wyll and Gale are conveniently human and could just set up on +2 studded with +1 shield. Astarion can also studded +2.
Karlach and Shadowheart could use +2 half plate, though it is likely only Shadowheart that wants a shield.
Of course Lae'zel can use the mighty full plate+2.
But if you compare full plate+2 to adamant splint armor, which is only ac 18, what wins? How about flawed Helldusk? Etc.
Does Wyll have Med Armour Proficiency? Most shields I have found in Act 1 & 2 are +2.
Decking out Wyll, Gale and Astarion would require three sets of Studded +2. How far into the game are you going to achieve that?
The basic +1 and +2 armours aren't that useful IMO. I find the 'Specials' much more useful.
Using the +2 Half Plate on Karlach would mean her Dex 20 was pointless.
Let's look at Barbarian.
Potentially, AC 20 with Dex 20 and Con 20.
You might get con 20 from the Barbarian garb that boosts AC and a natural of 18. But you just don't have the points for dex 20. So you're stuck with dex 18 with gloves of dex. And there's only one of those. That's AC 19.
Also AC 19: Half plate+2 and dex 14. The same dex 14 your cleric and druid probably have.
So what what weapon is this barbarian using? What is Str at?
In addition to the timing factor, the immunity to crits and the Reeling already mentioned, the Adamantine is slightly lighter than the Plate and gives -2 damage to all damage whereas the Full Plate +2 only gives the -2 to physical (S/P/B). Or at least that's how I read the wiki:
https://bg3.wiki/wiki/Adamantine_Splint_Armourhttps://bg3.wiki/wiki/Plate_Armour_%2B2
Also the Adamantine is 1.k more expensive than the Full Plate +2 - I use the price as a rough guide to usefulness/efficacy.
