So there has been some dis-satisfaction with how armor has evolved from concept and through development, and in the recent Q & A video, @jtoddcolemanand @thomasblair mentioned some of these issues and design desires that we haven't quite seen full-filled, such as armor set bonuses and motivating use of a combination of armor types as a means of creating visual variety. I have given this some thought and think I have what may not be a ground-breaking or unique set of ideas, with specific values or variables, but definitely a solid foundation and methodology which uses existing mechanics only, that might result in an improvement across the board.
Proposal demonstrating the principle:
Plate Chest has best Physical Resists, a Crit Defense Modifier Stat and all Plate pieces have a Health Regen Stat Mail Chest has best Organic Resists, a Healing Modifier Stat and all Mail pieces have a Mana Regen* Stat Leather Chest has best Elemental Resists, a Damage Modifier Stat and all Leather pieces have a Stamina Regen Stat
Plate Helms have a Hard Control Defense Stat Bonus Mail Helms have a Perception Stat Bonus Leather Helms have a Farsight Stat Bonus
Plate Gloves have a Weapon Weight Stat Bonus Mail Gloves have a Cooldown Reduction Bonus Leather Gloves have an Attack Control Defense Stat Bonus
Plate Boots have a Pathfinding Stat Bonus Mail Boots have a Movement Control Defense Stat Bonus Leather Boots have a Movement Speed Stat Bonus
This assignment of stats to armor pieces and type is based on a principle of logic and what the corresponding armor would actually do in the real world. If you had to choose between wearing a plate helm versus a leather helm, why would you choose either? A plate helm would provide more protection against head injuries, being stunned or knocked out etc, while a leather helm might grant better visibility. Mail Boots might grant good stability for your feet without being too heavy, while leather causes your feet to be lighter. And so on. Some of the example assignments above may be a stretch or seem arbitrary, but the overall principle is pretty clear.
The general idea here being to have the different pieces of different types grant specific stats, rewarding choice more than just slightly more or less in the same stat depending on which you choose. A nice thing about this system is how some of the existing stats work, and a way it can be taken advantage of to simulate set bonuses. Certain stats do not take effect unless said stat or a stat it relies on has either a minimum value - 1 versus .5 - or is a whole number. So 1.1 would effectively be the same as 1.9, whereas 2 would be twice as impacting, and you could have from 0.1 to 0.9 in a stat and have no effect, but once you reach 1, the related effects kick in. We see this currently with the Beneficial Harvesting set of stats for example.
So, for the 'All Pieces Regen Stats' I itemized below, if each of the 4 pieces granted .25 of a stat bonus, then the effect would only kick in if you wore all 4 pieces. This SHOULD allow set bonuses using existing code. Obviously this is in the greater overall context of existing stats and modifiers, some of which are likely to change in 5.8, so it may not or need not be the only stats possible on armor - other choices would need to be made as regards what can be added through the crafting process, with the materials recipes, the optional pieces and so on.
I prefer regen bonuses over straight pool size increases, especially for HP, as it gives some advantage but avoids the extremely high HP amounts which can be exploited by some classes. I see these increased gear stat modifiers as alternate paths to hitting the related caps, sooner than passive training would perhaps allow, in some cases acting as a temporary way to reach a stat goal, and one that could be set aside later in the account lifetime when training catches up, like we see done with many of the crafting stats. I think enhancing the association and strength of an armor type, the chest, in a particular damage category also makes logical sense and enables synergy with the other methods of acquiring resistance, such through the Disciplines.
Again, not a complete over-haul as it doesn't speak to the mitigation caps and so on, but a more defined foundation. Thoughts?