Totally agreed.
Mixing reds and yellows is starting to work and I really can see that with some tweaks here and there we could see a bloom of several hybrid builds.
However mixing blues with reds doesn't work very well. The damage lost is not compensated by a tiny gain in survivability.
Unfortunately, armor regeneration as a passive effect is currently too weak for that to really matter. As a secondary attribute, it caps out at 4,925 HP/second—even if you give up six secondary attribute slots for this, you're getting less than 30k HP / second, which isn't far off from a Tier 1 fixer drone (and the fixer drone isn't exactly a paragon of "keep you alive in a tight spot"), and you're giving up so much in attributes just to get to that mediocre result.
Now, there are also three sources of "% Armor Regeneration," but individually they're weak effects (all three are 1% each) and require significant sacrifices in order to achieve that.
And then there's bonus armor, which... snore.
The one thing it does seem to be consistently useful for is %Armor on Kill. But if you have a high base armor, you're probably not killing things very quickly, and on-kill bonuses are extremely devalued in group play.
I think if the secondary regeneration attributes and the blue gear mod attributes for armor-on-kill were stronger and scaled off armor base instead of flat numbers, it would be a lot more appealing. HSD and CHD are percentage bonuses that are magnified by your other damage bonuses. Why shouldn't Armor Regen (the secondary attributes) and Armor on Kill (the gear mods, not the brand/set bonuses) do the same?
Well i'm running Preservation on live, and its healing is pretty great.
Although i can agree, that defensive SECONDARY stats need some love.
Health - 18k health means nothing. Either it should go or increase it up to 60k per stat (360k won't help much, but at least it won't be useless).
Hazard protection - is fine as it is.
Explosive protection - a bit underwhelming. I think, it should roll higher, since there are not much sources of explosion, but their damage is super nuke-like. 15% per stat would help (55% with 3 stats and SHD will half the incoming damage, making it more viable).
Armor regen - as a stat, it should stay as absolute values, not %. However, buff it. Up to 10k/s. Or replace it with AoK in 10 seconds. So, 50k armor on kill in 10 seconds for each stat without refreshing. 300k armor in 10 seconds, after killing 5 enemies. Something like that.
Armor regen% - it should be buffed aswell. At least on Gila guard (it's a 3pc bonus btw). 2% would be enough.
BTW. To balance this, BLEED should block that incoming armor regen. And overall healing by 50%.