The Wizards adventure team had me worried with Keep on the Shadowfell. The poor quality material, recycled maps, multiple discrepencies between module rules and the core books, and overall poor production value had me concerned about the future of the adventure path. Thunderspire Labyrinth goes a long way to ease those fears.
First thing I noticed was the booklet material. MUCH nicer than the KotS booklets. The pages feel firm, and both the cover and interior pages are much more resistant to smudging and ink transfer. This was a huge problem for me with KotS, and I'm glad to see it corrected.
The map was both exciting and dissapointing. On one hand, it is a very nice map with multiple important areas from the adventure on it. On the other, it is only one double-sided map. KotS boasted 3 double sided full color poster maps, impressive even if they were mostly reprints of D&D miniature's maps with new markings.
The booklets are nicely organized. Book One contains the adventure hooks, first encounter, new monsters, important NPCs, a bird's-eye map of the area the adventure takes place, and a map with call-outs of the adventure's 'town'. It's nice to see these laid out all in their own section, as it makes the module much more useful for folks who just want the locations for inspiration. Book One also contains a random encounter table for overland travel, something sorely missed from the first adventure. Most eye-catching is the final 5 pages, which contain artwork of the area arrayed in an easy to cut out or photocopy section. This adds a great layer to the read-aloud text in the booklet, as you can hand your players a picture showing some of the most important locations in detail. There is also a section giving some direction in expanding the area around the Labyrinth, giving short descriptions of areas not directly covered by this adventure.
Booklet two is somewhat less impressive. Right off the bat, I noticed that it suffers from the same problem as the KotS adventure booklet: there is no back cover. The rear of the booklet is dedicated to details of the final encounter. The adventure's conclusion and aftermath is handled on the same page, in a single 7-line paragraph. While this is sufficient for the module, some might wish for more.
The bulk of Booklet Two is given over to details on the encounters in the adventure. Each area is presented much as it was in KotS: an overview, with full map and description of general features, followed by individual encounters. The overall maps have clearly marked features detailing encounters, and you could easily copy them and chop it up to hand to the players as they explore. The maps in general feel as if they were designed with a maximum of utility in mind: 10 foot wide halls are the norm, and everything looks as if it would be easy to recreate with a drawn playmat or with Dungeon Tiles.
The encounter entries are fairly standard. If you enjoyed the layout in KotS, you'll like these. They have been polished, brought to a higher standard of conformity. Seperated into sections for Setup, Roleplaying, monster stat blocks, Tactics, Features of the Area (including treasure), and Conclusion for lingering details that need handling, the encounters seem made to run smoothly out of the box. I anticipate very little advance prep-work needed for these encounters.
Overall, the adventure seems well written. I'll know more after we've been through it, but I'm looking forward to running it at this time. There is still room for improvement. In my opinion, the lack of a back cover, inclusion of only a single map, and heavy focus on combat encounters drop this product to 4 stars.