YMMV / Tyranny of Dragons

• Broken Base: There's some contention online over how good this campaign truly is, with very little middle ground. Those who like the campaign say that it appropriately builds up Tiamat as a threat and the Final Boss, making her into The Dreaded and a credible threat to the entire world. Also, Rise of Tiamat has the players taking on full-grown dragons and winning, making the campaign have a nice Catharsis Factor at watching the Cult of the Dragon fail. Those who dislike the campaign say that there's either too many characters or too many dangling plot hooks, and that the game balance isn't polished enough to make the difficulty consistent, especially because the module was written for the early release of Fifth Edition, causing many frustrating encounters. Regardless of whether one likes or dislikes Tyranny of Dragons, it really doesn't help that it came after Lost Mine of Phandelver, which is widely considered one of the best campaigns in all of Fifth Edition, and maybe one of the best in all of D&D, giving this campaign a tough reputation to try and live up to. The very few people who sit in the middle feel that the ideas and outline are good, but that it needs a lot of tweaking to make the module work as intended.
• It's the Same, Now It Sucks!: When it was announced that the re-released bundle for the campaign would have some changes, a number of players were hoping the module would be adjusted heavily to better balance the parts that were over tuned, particularly the opening section of Greenest and the Cult of the Dragons. Instead the re-release only makes a small number of adjustments, leaving it almost the exact same. Many were annoyed that despite having a good chance to improve the module and bring it to a salvageable state, they more or less did little except adjusting tiny elements that didn't fix much, especially since the re-release is expensive.
• Scrappy Mechanic: The council points system. In Rise of Tiamat, the council of various NPCs may or may not pledge their faction's help, depending on what the player characters did in Hoard of the Dragon Queen and for the rest of Rise. Not only are there ten different factions for the DM to keep track of, but some of the things that can lose you points with a faction don't even make sense on the Sliding Scale of Gameplay and Story Integration. For instance, the Order of the Gauntlet — Lawful Good paladins who worship Torm, the human god of justice and a friend to Bahamut the Platinum Dragon — will disapprove if you gave any concessions to a council of metallic dragons. Considering that metallic dragons are all some different flavor of a Good alignment, and that Bahamut is the god of all metallic dragons, it's baffling as to why having metallic dragons on the party's side would cause the Order to be less likely to help. Many guides to Rise have suggestions on how to tweak this mechanic to be more straightforward; a few of them even suggest outright ignoring it.invoked
• That One Level: The opening in Greenest is said to be one of the hardest parts of the entire campaign, if not the hardest. The roaming packs of kobolds and cultists are all weak enemies, but there's just so many of them that all the damage adds up quickly, since everybody's at level 1 and likely don't have ways to mitigate damage or deal with large groups. The boss encounters with Lennithon the adult blue dragon and Langedrosa Cyanwrath the half-dragon fighter are meant to be Hopeless Boss Fights, but they can still potentially kill the early-game characters with one bad roll of the dice. Things do get better after that in terms of difficulty, but it's a rough way to start. Later modules would be much better balanced in the opening stages by comparison, and many DM guide videos on YouTube about the module suggest toning down how hard it is.
• They Wasted a Perfectly Good Character: Despite having a perfect opportunity to include him, Bahamut the Platinum Dragon makes no appearance in the campaign outside of being talked about a few times. What makes this strange is that Bahamut is a god who often travels as a mortal to see how good people really are, Tiamat's only sibling as well as her Arch-Enemy, and the God of Good for all dragons. Bahamut easily could have appeared in Tyranny of Dragons to offer help in some way, but he never shows up anywhere in the module as written. Fan guides for running the campaign suggest including Bahamut in some form anyway because he's been known to act in a more hands-on way whenever Tiamat is involved — her resurrection would certainly count as desperate enough for Bahamut to intervene directly.