Jetdoc... theres a difference between a Warrior who brings Mending to heal and a Warrior who brings Healing Signet.
The 1 with Mending survives a shed load of niggly bits of damage
The 1 with Healing Signet takes a bit, then heals himself back up when he feels fit.
Now put these 2 in areas where they obviously are too dim to realise how useful the skill is.
Mending, the mesmer spams Degen, Shatters his enchantment and as half of the warriors with mending do, recast it.... then get Power Spiked or just shattered again.
Healing Signet, he gets degened and heals it off when it starts to dig in.
There is nothing wrong with Mending as such, its just people don't know when to us it! The number of people who cast it on Chest Runs it just makes you wonder if they've realised the first group of enemies you run through will Shatter it instantly. When your solo farming, fair enough, its brilliant (not for all areas obviously). When your going round FoW or UW with a full team? What is wrong with you!?
If you have an even slightly competant monk with you, mending shouldn't matter, by leaving stat points out of Tactics to bring Mending instead, you could've used that slot to bring Watch Yourself, benefiting your entire team, not just yourself.
I haven't been paying attention to the threads related to Warrior armours, but no i didn't know that Knights bonus' didn't stack, i also didn't know that when i bought it.
BUT as you rightly said, i did buy it for looks, i have absolutely no use for the +1 Strength on the helm in just about every situation i can think of, but the rest of the helms look absolutely shit in all honesty (female warrior btw). 15k Gladiators Leggings/Hauberk ftw

Its my only char i bought the armour mainly to look good on.