A classic advenutre! I am running players through this dungeon right now (with 5th edition convertions). Has all the feel of the old school dungeon you WANT.
Only gripe I have is that the map scans are awful! They are low-res, blurry and the map appears in pieces (multiple pages in the PDF). It is a challenge to figure out how the pieces of the map all link together. Once you understand where each piece of the map links to, it continues to be a challenge as you reference the map while playing. For an adventure that relies on an extremely complex and intricate map, it is VERY challenging to run this adventure while referring to the terrible maps in this PDF. I tried looking for other places to get the maps for this, but they are out of print (or for sale on Amazon at over $100!). So there isn't any option but to use the maps they have in this PDF for the adventure.
Hopefully they have a re-scan of the maps in the future like they have done with a few other products I have seen. It is the only reason I have not given this product 5 stars. Because otherwise, this is a really fun adventure.
[4 of 5 Stars!]