There is a great, relatively comprehensive review written by a friend of mine, posted on RPGGeek, here:
Worthwhile addition to your hoard, except the maps
In case you don't want to read the whole thing, here are the basics of his review:
1) Hoard of the Dragon Queen is a strong, but not quite excellent, campaign-length adventure to kick off D&D 5E.
2) It takes PCs up to 8th level, but some railroading will have to accepted to get there.
3) The episodes contain a variety of adventure styles - dungeon crawls, social episodes, and some investigation. This adventure will require more thinking and planning than the vast majority of those seen for recent D&D editions or Pathfinder.
4) There is not a huge variety of antagonists for 7-8 levels of play - mostly the same humanoids with only a few interesting/different creatures.
5) The treasure is also very boring.
6) The presentation hearkens back to older design in that it often presents a location with which the PCs can interact, without imposing an encounter structure.
7) It’s also important to note that Hoard of the Dragon Queen doesn’t have a conclusion. You’ll need to make up your own if you are running this on its own – or of course look out for the sequel, The Rise of Tiamat, in fall 2014.
And last but not least:
8) There are a few problems with the maps and some description editing stuff in the product:
**Note, the following contains spoilers, so skip it if you don't want to read them!*** - I will put them in spoilery light blue colors to try and mitigate the spoilery-ness - highlight them with your mouse to see them.
Episode 1:
The Greenest town map on p. 10 has keyed areas 1-4, but the text only mentions areas 1 (the Keep) and 2 (the Old Tunnel exit). It looks as though area 3 is the temple to Chauntea and area 4 is the town mill, both significant to the episode.
Episode 3:
Area 10: Issue with the roper "willing to talk" but then stats don't list languages, so it looks like the adventure designers and the monster team have come to different visions of the roper. In 3.5, ropers were intelligent, so Baur and Winters were probably assuming they could use that version.
Episode 5:
In the text on p. 39, there's a dangling antecedent which caused me some confusion on initial reading: "Azbara Jos remains with the cultists during this time, and Jamna expresses her desire to remain with them until they uncover the treasure's destination." Jamna wants to remain with the PCs, not with the cultists.
The map of Carnath Roadhouse on p. 41 appears to be missing a red "door" indicator in the gap in the northern wall of the warehouse (area 3), just west of the stairs to the upper level. The text says the warehouse door is "latched but unlocked".
Area 12: This refers to four of the guards being at the entrance at any one time, but Area 1 actually has only 2 creatures (and they aren't the same type as those in area 12 anyway).
Episode 6:
Area 2H: The description clearly describes itself as sitting above the forge (1H), but this room doesn't. The solution is simply to switch the H and K labels on the Level 2 map of the Castle.
In area 1I/J/K (p. 53), are there twelve lizardfolk guards, as noted in the first paragraph of 1I, or twenty, as suggested by adding the numbers from 1J and 1K? I'm assuming it's twenty.
And in area 3E (p. 57), are there six specters or just three? I'm assuming it's six, since three CR1 specters are a pretty weak challenge for a 5th-level party, but it'd be nice to know for sure.
Episode 7:
Level 2 of the map is all screwed up. There definitely shouldn't be an area 14 here.
There should only be one area 18, but there are three. Some of these are supposed to be the bodyguard's chambers, but there are four of those. And there's another room with four beds that could work instead.
Probably the southernmost room marked "18" is Talis's bedchamber (Area 18): it has the "burgundy bedspread" mentioned in the room description. The four-bed room is marked "19", which is right if it's the bodyguards' room (Area 19).
So it looks to me as though the issues are that the two northern "18" rooms should just be (empty?) guest bedrooms, and that the room marked "14" is not described and is not Area 14 from the lower level. (Oh, and that Area 22 isn't marked on the map at all, though it's pretty clear from the description that it's above Area 18.)