+20% entchantment grip. why its useful?

i play gw form the beginning. i have 4 charakter warrior, monk, memser and ranger.

but i never used an 20% enchantment grip. what exactly does it do? can someone give me a good example so i understand it cleary?

Well if you use any of these skills, they last 20% longer:

Mesmer: Illusion of Haste, Illusion of Weakness, Illusionary Weaponry, Sympatheic Visage, Channeling, Arcane Echo, Echo

Elementalist: Air attunement, Fire attunement, Earth attunement, Water attunement, Conjure Air, Conjure Fire, Conjure Water, Conjure Earth, Windborne Speed, Armor of Earth, Kinetic Armor, Magnetic Aura, Obsidian Flesh, Elemental Attunement, Ether Prodigy, Ether Renewal, Aura of Restoration, Armor of Frost, Armor of Mist, Mist Form, Swirling Aura

Monk: Aura of Faith, Blessed Aura, Divine Intervention, Peace and Harmony, Spell Breaker, Healing Breeze, Healing Hands, Healing Seed, Vigorous Spirit, Aegis, Guardian, Mark of Protection, Protective Spirit, Reversal of Fortune, Shield of Deflection, Shield of Regeneration, Shielding Hands, Judge's Insight, Shield of Judgement, Zealot's Fire.

Necro: Awaken the Blood, Blood Renewal, Blood Ritual, Blood is Power, Dark Bond, Dark Fury, Dark Pact, Demonic Flesh, Order of the Vampire, Order of Pain, Aura of the Lich, Dark Aura, Death Nova, Tainted Flesh

A pretty impressive list.

For a specific example, look at healing breeze. It normally heals, let's say 10 pips of health for 10 seconds. That's 10 pips x 2 health/pip x 10 seconds = 200 health. Now, with a 20% enchant mod, breeze lasts 12 seconds, so that's 10 pip x 20 health/pip x 12 seconds = 240 health. So in other words, just for carrying the mod around, you heal an extra 40 health. And that's just the tip of the iceberg. Effectively, you make the spell effect, whatever it may be, 20% better just by using the item. Here's another example, consider Aegis... at 12 skill, you get 10 seconds of duration. Using the 20% enchant mod, it lasts 12 seconds, equivalent to the value of something like 15 skill. So the 20% mod in this case works effectively as a superior protection rune!

Rico

What you have to realise is that usually people switch to enchant weapon when they cast their enchantment, then switch back to their normal set.

not only that, but in conjunction with a 30-37% blessed aura you can overlap quite a few enchantments, since the duration can outlast the cooldown.

its especially useful for skills like shield of judgement, spellbreaker, healing hands, sympathetic visage and mark of protection.

IoW isn't a time thing... It triggers when you're health goes below a certain amount (25% if im not mistaken). So the ench mod wouldnt help there. Other than that, nice list

i have a question to mark of protetion. so its possible to cast it always, without a cooldown time?

No, Mark of Protection normally lasts 10 seconds. With an enchantment mod and the monk skill that increases enchantment last time, it still would not be possible to get Mark of Protection above 20 seconds (I think it'd be 15 seconds) let alone the needed 45 seconds that MoP takes to recharge.

no, i merely gave a list of skills that it greatly increases in effectiveness.
one of the primary downsides to mark of protection is that the duration (10 secconds) is equal to the time it disables your protection skills (also 10 secconds) with blessed and a 20% ench pommel it increases the duration to 15, which is substancial for what mark of protection actually does.

it should be noted that neither blessed aura or a 20% ench pommel increase the duration of vengeance.

Dark Pact is a direct damage attack spell, not an enchantment.