Blaster Warlock outpaces the Blade Warlock easily, especially at higher levels, if you're just looking at raw numbers. There are mechanic aspects many of you ignore when you crunch the numbers.
1) Being in melee allows for opportunity attacks, potentially increasing damage (see my post on page #3 regarding the nasty combo of War Caster and Pole Arm Master to cast Eldritch Blast as a reaction).
2) Being a weapon means that you can get +1 or better versions of it. From the released Magic Items we've seen so far the design seems to be going towards allowing DC increases for spells, but not necessarily bonuses to attack rolls or damage rolls on spells (though anything is possible). The point being, that getting a +1 Weapon is far more likely than getting a special weapon that does something similar for Eldritch Blast (though I admit of all the spells, it's the most likely one to get an item dedicated to it since it's so iconic).
As to Agonizing Blast - it applies to each hit of Eldritch Blast. It specifically says "add your Charisma modifier to the damage it deals on a hit". Each roll is a separate chance to hit or miss independent of the others. The comment people refer to where they assume it doesn't apply is the Magic Missile & Empowered Evocations question Mike Mearls answered. He said that if you hit separate targets it would get your Int to damage on both, but not if they all hit the same target since it was one damage roll. I see his logic there, since Magic Missile deals damage simultaneously and doesn't have a to 'hit' you're just assigning dice between targets, since Empowered Envocations adds to the 'damage roll' it only applies to each individual roll. Meanwhile, Scorching Ray would likely gain the bonus to each attack since each hit/roll is separate.
1) Being in melee allows for opportunity attacks, potentially increasing damage (see my post on page #3 regarding the nasty combo of War Caster and Pole Arm Master to cast Eldritch Blast as a reaction).
2) Being a weapon means that you can get +1 or better versions of it. From the released Magic Items we've seen so far the design seems to be going towards allowing DC increases for spells, but not necessarily bonuses to attack rolls or damage rolls on spells (though anything is possible). The point being, that getting a +1 Weapon is far more likely than getting a special weapon that does something similar for Eldritch Blast (though I admit of all the spells, it's the most likely one to get an item dedicated to it since it's so iconic).
As to Agonizing Blast - it applies to each hit of Eldritch Blast. It specifically says "add your Charisma modifier to the damage it deals on a hit". Each roll is a separate chance to hit or miss independent of the others. The comment people refer to where they assume it doesn't apply is the Magic Missile & Empowered Evocations question Mike Mearls answered. He said that if you hit separate targets it would get your Int to damage on both, but not if they all hit the same target since it was one damage roll. I see his logic there, since Magic Missile deals damage simultaneously and doesn't have a to 'hit' you're just assigning dice between targets, since Empowered Envocations adds to the 'damage roll' it only applies to each individual roll. Meanwhile, Scorching Ray would likely gain the bonus to each attack since each hit/roll is separate.