I know that eps have to air first before they can be fairly judged, but here's my 2 cents on what we know so far...
9.10 Road Trip
Dean (Jensen Ackles) is devastated after Kevin’s death and vows to find the angel that killed him, not only to free Sam (Jared Padalecki), but to seek revenge. Castiel (Misha Collins) arrives at the bunker and suggests they try to separate Sam’s brain from the angel’s so they can talk to Sam and have him expel Gadreel. However, there’s one small problem: the only person who knows how to do that is Crowley (Mark Sheppard).
9.11 First Born
Looking to reclaim his place as King of Hell, Crowley (Mark Sheppard) asks Dean (Jensen Ackles) for help finding “The First Blade,” the only blade that can kill Abbadon (guest star Alaina Huffman). Knowing he owes Crowley a favor for helping Sam (Jared Padalecki), and also wanting Abaddon dead himself, Dean reluctantly agrees and the two set off on a road trip. However, Dean and Crowley are completely unprepared when they find out who has the blade - Cain (guest star Omundson), the first son. Meanwhile, Sam is back at the bunker with Castiel (Misha Collins) who notices there is some leftover grace inside Sam. If they can extract it, they can use the grace to track Gadreel. The only problem is the procedure may do permanent damage to Sam. John Badham directed the episode written by Robbie Thompson.
Ok, so Dean wants "revenge" on Gadreel for killing Kevin. He turns to Crowley for help in freeing Sam (and Crowley succeeds). Dean not only frees Crowley for doing this, but he owes him a favor (searching for the blade that can kill Abaddon).
I understand that Dean is upset over Kevin's death, and upset that Gadreel betrayed him. But... what about Crowley? Crowley killed Sarah, but neither Sam nor Dean wanted revenge on Crowley because of it. He killed Kevin's girlfriend, but nothing was made of that, either. Crowley was going to kill everyone they ever saved. He's the freakin' King of Hell (or he was), he's done countless bad things, but his only "punishment" has been to sit in the Men of Letter's dungeon, alone. And now he's going to be rewarded, not only with his freedom, but with Dean helping him on one of his own missions.
So, because Crowley is "useful", he gets released. Gadreel was useful, too. He saved Sam's life in 9.01 (and many times after that). He saved Cas and Charlie, too. If we had a scorecard, I'm sure that Crowley has done a lot more "bad" than Gadreel has. But somehow, that's all getting ignored.
And what about Sam? The only way to separate "Sam's brain from the angel's" involves torture (as seen on the promo). And they trust Crowley to do this? And somehow, it's ok for Crowley to torture Gadreel, and he gets rewarded for it? And then in 9.11, the procedure to extract the grace could do permanent damage to Sam. They'd really risk harming Sam like this?