I'm a beginning keeper and at the time of writing only part way through the campaign but we're really enjoying it. My players are really enjoying the largely freeroam/sandbox nature of the material and although they aren't in any way tied to rails the material is written in a way that allows the overall campaign to stay on track.
One word of warning I do have is with the beautiful journals that are produced as handouts for this, I found that they contain some material that seems at odds with what's in the campaign itself. Certainly the Neve Selcibuc journal dropped a lot of red herrings that were difficult to deal with especially given the sandbox nature of the first chapter.
I would thoroughly recommend this, we're having a blast with it. While it's far from necessary the London box set that Cubicle 7 produce is also recommended. I'd consider carefully though buying and handing out the journals.
[4 of 5 Stars!]