No you haven't. I'm rather pleased with that one, myself.

Overall I like this class. It can't compete with the big 3, but it has a daily versatility thats nice, and something beyond 'I hit it in the face again'. The flavor is kinda lame, what with summoning the remnants of Powers That Were being automatically successful and not doing anything to you beyond an obnoxious personal habit for the duration. But hey, you can do quirky shit. And all your Save- based powers actually scale with your goddamn level. Hurray!
My overall thoughts on the vestiges go something like this-
Acerak- Meh. Unless you're playing a murder mystery where speak with dead at will matters, or really need to be immune to cold and lightning.
Agares- Need to talk to people at the tower of Babel? Here you go. The fear immunity is a joke, since its a fucking class feature, and unless you're using improved binding to bind this joker at level 5, you already have it. You can have a minion, though.
Amon- Mediocre. Fire breath scales, but its still just a line of fire.
Andras- Good for some combat builds. Especially mounted chargers.
Sow Discord is a nice break from stabbing people, since you can make other people stab their friends.
Andromalius- I really wanted to be a rogue! But see invisibility is good, and it stacks with Malphas' sudden strike in a way that turns out to be level appropriate sometimes. Locate Item also allows you break some quests.
Aym- Yeah. You can break shit. And if you really need to breach DR/adamantine, she's your dwarf bitch.
Balam- Rerolls and some bonuses that get fairly large and stack with a bunch of shit (but not your class feature).
Buer- the cleric's medipack bitch. Clerics will love you, because now they have even less reason to be the healbitch.
Chupoclops- awesome. someone just gave you a shitload of cool abilities for no apparent reason. You can pounce on people. From another plane. Works well with a bunch of other vestiges. Potentially downright fucking ridiculous once you can bind 3 or 4
Dahlver-Nar- a bunch of crap coupled with the ability to take half damage and inflict on something else. Meh.
Dantalion- Once every 5 rounds, anyone that can see you can't attack you for a round. No save. Just openly deny. As a move action. And you can read minds and have a short range dimension door. Nice.
Eligor- another combat guy. The other half of the binder charge build.
Eurynome- sucks more ass than that dead elf bitch. Seriously, her most useful power is water walking. Buy the damn ring if you really need it.
Focalor- Pretty good, especially at low levels, very good with improved binding at level 3. Inflict penalties, blind and zap people. Oh, and breath water.
Geryon- Another worthless piece of shit. Fly for one round every 5? Bite me. Tenebrous gives see in darkness too. At a lower level.
Haagenti- You can use axes! Shut up, bitch.
Halphax- Board control++. Wall of Iron? Check. Imprison by fucking touch, check. Create a fucking 20' square stone tower at will? Fucking awesome. Always fight from a backstop. DR 10/adamatine would be decent if you weren't at least 15th level. But at least you're mostly immune to angry mobs that are pissed about the real estate fluctuations.
Haures- Mind blank at level 10? Not bad. Incorporeal movement? Also not bad.
Rogue killer every five roundsl? Also pretty nice.
Major image every five rounds? Fucking awesome. The RP options for this guy are also amazing. Go on. Be a crazy bastard. You know you want to. You are required to talk to imaginary people, but you can also totally make them. Show off the wacky shit that should just go on inside your head.
Ipos- mediocre. Being able to survive on any plane is fairly situational. Rending isn't bad, exactly, but you need something to make your claws better. The gem is the swift action true seeing. Shame about the duration. Also useful for pushing the save DCs up really, really high.
Karsus- detect magic at will, and use arcane staves and wands at a +2 DC. Artillery specialist.
Leraje- did her. stupid bitch in life, stupid bitch in death.
Malphas- pretty good summary above. Good low level scout
Marchosias- death attack, gaseous form, absurd bonus to hide and move silently. Why do you have to be 13th level for this crap?
Naberius- Speak, ubu, speak. Good dog.
Orthos- Blindsight, permanent Displacement and [level]d6 untyped magical damage. Nice.
Otiax- A ranged touch attack that would be level appropriate at level 3. And you can open really shitty locks. At 8th level.
Paimon- untyped dex bonus, uncanny dodge and the ability to attack everybody in reach, all the time, all at 3rd level with the right feat. Nice.
Ronove- yeah. She exists. She doesn't totally suck.
Savnok- free Full Plate. Um. And you can swap with allies, if they're really close. At levels 1 and 2, the armor might be worth it. By 5th, it almost certainly isn't.
Shax- meh. Freedom of movement is good. 1 round out of every 5, not so good. A swim speed too. Gosh.
Tenebrous- not bad. Permanent concealment that you can see out of. Turn undead is useful if you can talk your DM into letting you use it for divine feats that just require you to spend a single turn attempt. Limited teleportation.
Zagan- Weird. Improved Grapple and you count as large, and you can constrict (and you can apply your pact augmentation damage bonus to the constrict damage rolls). So you can beat other humanoids in a wrestling match. Not horrid. And you can really kill snakes and snakelike critters. Aversion is pretty nice if you actually want to keep people away. There are worse options.