Expedition to Castle Ravenloft is going to be my bedtime reading for the next week or so. I have found some stuff to like about it, but I'm just looking for a reason to play this version instead of an updated I6.
The more I check it out, the less I like the tactical encounter format. It's a good idea in theory, trying to put everything you need in one spot and all that. It's a welcome change from the 30+ page glut of stat blocks at the end of adventures. Return to the Temple of Elemental Evil, City of the Spider Queen, anyone? But overall, it eats up ALOT of page space. Going back and forth from a room description to a seperate page for encounters still keeps you either Xeroxing or sticky-noting things. Not only this, but I feel like having EVERY little detail plotted out for the critters is kinda redundant. As a DM, I feel more like I'm watching the battles unfold than I'm plotting them. I expect the major villains, critters with complex abilities, and big fish to have tactical layouts approaching this degree of complexity. But this level of detail isn't necessary for a pack of zombies, for crying out loud.
The other things I've already said about it still stick in my craw. Of course I can wikipedia/google/whatever around to patch together a physical description of Chernovog and all (not to mention the motivations, personality, goals and cults of a brand-spanking-new demon prince that's been dropped smack dab into the adventure as little more than a footnote to an encounter), but I really don't think I should have to. Getting a stat block and calling it a "creature" is like someone handing you a box of cake mix and some eggs when you order dessert at your favorite restaurant. Okay, maybe something got FUBARed in the editing. Whatever. In all fairness, there was no credited proofreader on the title page. Little things like this make the veins in my forehead pound when I see a MSRP of $34.95 on a hardcover adventure that's designed to span 5 levels. This cries out for a web enhancement or an errata to patch these gaps.
I don't know if it's because they crank out so many new products over so short a time or what, but the overall quality of the proofreading has gone way down in the D&D line. People in my FLGS even bet on how many typos or rules errors they are going to find in a new splatbook when it comes out. I know that I can't speak for everyone, but I am recommending that you take a second look at Expedition to Castle Ravenloft before you buy it.