We signed with Consortium late last year, and I love them. Our sales have doubled since going with them. Their marketing and publicity teams are fabulous, and I'm always getting emails from them telling me that they're pitching our lead titles to various nontraditional marketplaces because they see a fit - over and above our books being placed in traditional marketplaces.
They have excellent relationships with reviewers, so our books are getting requests to be review in places like Shelfari and Booklist.
They are small on purpose, so I have no problems with correspondence. It's not unusual to ask them for feedback on cover art or title ideas.
Additionally, they have sales teams who cover all territories in the US and Canada, so not only do we have national placement, but the sales teams go into the stores to pitch our books.
They are picky about whom they offer contracts to. They want to see that you have a healthy front list and backlist, and that your sales are very strong and consistent. Can't say enough nice things about them.