Taking EK on a melee makes your melee worse (If you don't pretend that those EK levels don't otherwise exist).
Taking EK on a caster makes your caster worse.
Eldritch Knight offensive potential is not epic significant.
- EK ranks give only half as much spellpower as Archmage ranks. Spellpower potential => Reduced.
- Equipping a spellpower weapon instead of a dps weapon makes your overall dps much worse.
- Eldritch strike does just a bit over 100 damage every 15 seconds (about 7 dps), including spellsword element. Not scalable by critting.
- Eldritch strike costs 10sp.
- Spellsword is not amplified by spellpower, damage boosts, master's blitz, spell crit, or weapon crit. It does not crit. Again, does not scale effectively.
- Spellsword does not work with ranged weapons. No you can't multi-spellsword-shot something.
- Average melee hit under master's blitz: 200 base physical damage + 10 spellsword damage. Total spellsword damage contribution is 5% and required investing the 18 arcane levels.
- If you make 2.5 attacks per second, and spellsword costs 1sp/6s => 150 damage per spell point. Efficiency will probably be worse unless you're continuosly beating on the same target for ages (likely).
- Eldritch strike (compared to a cleave), assuming 100 ES damage / 10 sp = 10 damage (per target) per spell point. I'm sure you can think of better ways of spending spellpoints.
- Eldritch Tempest is not crowd control. 1s of KD every 40 seconds is not useful CC.
- Eldritch Tempest (compared to a cleave)does about 150 additional damage for 30sp. Efficency: 150/30= only 5 damage (per target) per spell point. Ewwwww?
- Eldritch Tempest does about (150 damage / 30s) = 5 damage per second if spammed. How long does it take to kill an EE/EH/EN monster with 5 dps?
- Severely restricted damage amplification potential => No real synergy with any Epic Destinies. No synergies make for poor builds. (contrast: abilities that increase average base damage via crits synergizes with everything)
- EK offensive potential does not hold its own, and is not in any way competitive with the synergized results of other offensive build strategies.
- What could levels of kensei have offered instead?
Tested on a 18 wizard(EK/PM)/2 rogue (acrobat) with 140spellpower. Character has just average gear and numbers can be a bit improved, but consider points #1 and #2.