DiamondProc (Nosferatu) is a knowledgeable and skilled player who was helpful enough to create this guide for new players. All credit goes to him for making this available. Thanks again for sharing this information my friend and hopefully helping the AO Community.
I've also put some of this information into a video, but I think that it's much better in Diamond's printed guide below:
ARMOR - HELMS
Without further ado, let's get started with helms.
Great use for tank's such as quarter staff users and or healer's .. utilized mainly when you expect to be focused ** it will lower your attack damage which is why it is not recommended for DPS**
Combine this with anti-zerg mechanics when getting attacked by multiple target's and you pretty much have a 10s window where you are virtually unkillable.
This heal can be really good for 1v1 combat, many time's when I am out looking to kill someone I will save this heal for the correct moment when I can turn the tide on a fight.
It also offers a small radius heal that can be useful in small groups to give everyone a little extra hp during a fight, or while regrouping.
Retaliate is kind of a niche spell on the plate helm, it honestly can be useful for pvp and pve, yet it compromises your Armor/Resist for what I find to be a rather lack luster thorn effect. In my personal experience, the defensive spells have outweighed the 'offensive' Retaliate.
Reflection is pretty much a useless stat, while it seems to synergize with retaliate , the actual spell does not outweigh the other two at all.
Toughness & Constitution from all test's ive been a part of , actually give equal mitigation. So pick the one you like best!
I rate this as bad/semi useful, while being immune to CC seems like a no brainer I have found in testing this that it simply has not lived up to other helm's abilities.
On paper, and through further testing.. this could seem to be a very good spell that could find it's way someday.
Meditation is very useful for 'resetting' cool downs. As a healer it was very nice because I could do back to back desperate prayers, it also grants great cool down relief for abilities with 30s~+ cool downs.
I would say this spell is great for niche builds, but as an overall skill you could find better spell's to replace it.
Maybe one of the best abilities on the medium helm for several reasons.
It has great gap closing potential, although it lowers your armor, you typically use it because you need to close or extend a gap. So usually you won't find yourself casting this in an actual fight, but rather to maybe cap a stone in a GvG or escape while you are gathering and or farming.
Move speed pretty much is king in the passive tree, although the passive's are small.. movement speed is one of the most important aspects of the game. This is also a good reason why defenseless rush is so important, the ability to actually catch someone and lock them down is what currently dominates the state of the game.
My experience with things like CC duration's and movement impairing effect's (essentially CC in general) is that once you get caught , unless you have an ability like blink.. you are pretty much in trouble. So these small reduced CC amounts are why move speed in general takes the cake, the idea is do not get caught at all and you will have a much greater impact on your survival / someone else's death.
Magic focus is a really good spell that can really boost your damage, the core issue here is the 8 second move speed reduction by 75%. This creates an extremely niche fit for this spell. Maybe for dropping a meteor on a castle defense, but honestly I would say there are better options.
This is where my bias could really start to come into play, but I think anytime you get free energy regain it has to be considered one of the better options in the game. While there are other option's for this such as potions, the 1 min cooldown is pretty hard not to like.
I would say as an alternative to magic focus, this would take the cake by far. Increasing your actual magical & physical damage by 38% simply for the loss of armor only, and it's for 10 seconds! Light helm's are really hard not to like when it comes to being offensive.
Aggression & Charity are pretty straight forward.
Concentration is something I have experimented with and the results can be interesting, while I really like the cast speed.. I find that quality work's for me over quantity. If we were to number crunch, actually getting more cast's off might be better, but I look at it from a healer's perspective, one large desperate prayer heal could outweigh being able to cast multiple flash heals quickly.