First off, I want to dispel a couple of rumors:
1. "Wailer" is NOT some aquatic farcical play on words that manifested itself in the form of whaler, whaling, or any whale related cards in the AP.
2. There are NO Bob Marley related cards, though Wraith could develop dreadlocks if it does not watch out...
Disclaimer: I am too lazy to write out complete text and of course the comments are just my opinion so please do not take anything too seriously...
Agency
Sam Archer seems well suited to Agency/MU synergy. Think Anthropology Adviser+Beneath the Surface, etc. . He is a Unique Investigator for 5 with 4 skill, dual skulls and glasses, Willpower, +2 toughness, Heroic... bassically a beast who can pay 1 to get more glass.
MU
Derby Hall is a Unique Location for 2 that lets you pay 1+Exhaust to return a Student or Faculty into your hand. Since the better Professors are not Faculty this thing blows. Why is it Unique? It does not make me think of it as more special...
Syndicate
Have you SEEN Eyes in a Jar? LOL! Anyway, I am loving this card. What better way to add to the sleazing stories strategy of Syndicate than knowing your opponent's every move. No question mark there becasue that was a statement.
Cthulhu
Degenerate Serpent Cultist is the best Cthulhu turn 1 yet. One Terror 2 skill and the ability to pay 1 to change Terror to book for phase for some hit and run fun. Oh yea, it has the Serpent and Cultist traits (Carl eats snake). Really, it looks like a snake crawling out of some robes. Terror and 2 Skill will keep down the number of success tokens layed down by Investigator decks so the big boys can clean house later on.
Hastur
They got nothing to support their broken deck (birds, steps, etc), so cheers on that front. Renowned Sculpter cost 2-skill 3-book and can drive self insane to put an Artifact or Item into play for free then return to hand at end of phase. Please never bring back Shining Trapezohedron. Thank the powers that be that he cannot do this with Locations!
Yog Sothoth
Doppelganger is a Character that you pay X when it comes into play for it to become an exact copy of an X cost non-unique Character. Good so far, IMO balanced... Please don't add any more text... Oops, if Character it copied leaves play return Doppelganger to your hand. IDK it seems like the Yog cards are pushing toward supporting Mill decks. Oh joy! Anyway, if someone sees a good use for Ms. Doppelopolis LMK.
Shub Niggurath
Speaking of Eyes, like back in the Syndicate section... Optic Warehouse is a 2 cost support card that you can exhaust and pay 2 to have it add or remove a Terror struggle. Got Mi-Go? This card also has potential with some out of Faction combo decks. The Ghouls is also a good card but I am sticking to one per faction for right now...
Overall I would say MU-Hastur-Yog got the low end, Agency in the middle, Syndicate-Cthulhu-Shub did the best. Remember, this is just an opinion based on fist impressions. 



