I can only speak up to Adventure 5, but these are good. A couple of things I can add from our playing Zeitgeist for the past two years:
Adventure 1: I had to scrap the tower defense rules as it was too abstract for my players. Also, the final fight with Asrabey went really fast if you have a gunslinger in the group. Not sure what one can do to really defend against that. It was kinda like that scene in Indiana Jones....Asrabey was super-cool sword slinging, and the gunslinger just drew her pistol and took him out in one shot.
Adventure 2: The hardest part for my group was making the connection between Macbannin and Nilasa aka the murder victim. The group wanted to go after the person who actually pulled the trigger and didn't want to get involved in politics by messing around with the Mayor. I had to make up a new piece of evidence - a hand written note from Macbannin to 'the murderer' thanking him for stopping her and preventing her from revealing what they were doing. This was literally the only time the group felt railroaded into doing something they didn't want to do. I used the statted up Macbannin, which made the fight last several rounds, it was one of their more exciting battles as I recall. Also, I recommend running the Bonds of Forced Faith prior to this adventure. My players were terrified of heading up to Cauldron Hill - as they should have been.
Adventure 3: My group enjoyed the rainbow puzzle. This was definitely my group's most favorite adventure. Everything about it hit each of their pleasure buttons. The fight at the end, with all the phasing, can be a bit complicated but it's very fun and satisfying. One thing to note though, either don't use the RHC constables listed in the adventure to protect Saxby OR do use them, but use a different group of RHC constables as Team B in Adventure 5. My players never trusted those constables after that fight and didn't want anything to do with them afterwards.
Adventure 4: I think my group is exact opposite of most others I've seen on the boards. They just couldn't get into spy mode and did not like sitting on the train, nor did they want to RP with anyone on it. This one is my fault as the DM though. I made the mistake of overly emphasizing 'stay in character and don't get caught' instead of equally emphasizing that and 'discover who the Ob person on the train is and figure out what's up'. A few players didn't get why they were going after this Ob in the first place, a few kinda did - danger to Risur and it was RHC's mission to protect Risur from outside threats, ect. My group was paralyzed with fear of getting discovered on the train, so didn't do much of anything while on it and only went out in the enclaves maybe a couple of times....missed out on most of the adventure. They even hid and didn't fight the Malice Beast.....caused the max number of casualties for that. But to that end, because of their paranoia, the Ob never did discover who they were until the very end (and only because the Ob did an off-scene divination ritual to discover their identities). I still ran the ghost train, but they never figured out the who or why it happened. And only one PC made it to the meeting, hid the whole time, and just reported back to the rest of the group, who decided to wait at the enclave in Vendricce.
Adventure 5: As mentioned in Adventure 3, my group did not trust the Team B constables and did not want to play them. They were certain they were still in league with Saxby and probably the Ob too. So I had to run all of Team B's stuff off-screen and just have Delft tell them what's up. But the parts that they did play through....Ekossigan, the eschatologists, the dinner party, the bomb, the Bleak Gate....they enjoyed. But I did have a couple of players start grumbling about how none of this made any sense and didn't see how any of what they were doing fit any overall story arc. So if I do run this again, I will have to clarify what they are doing a little better maybe. Half the group loved the strike team mechanics. The other half could have cared less. So it's a coin toss as to whether other groups are gonna dig it or not. I think it's fairly balanced though, the group almost didn't make the successes in time to find Kell, so for those players that got into the strike team mechanics, they were getting nervous. Also, don't forget that Kell's and the two bodyguard's stats are located in the back of the book in the appendixes, not in the main body of the adventure. I made the mistake of not printing those out, so had to guess as to what they could do during the session. Also....naval rules....way too abstract for my players. About halfway through using them, they gave up and I just had to narrate the rest of the battle.
My group decided to end at Adventure 5, for now anyway. In the end, my advice to is make sure the players are 1) in for a long, long campaign; we played for two years on a weekly basis and only got to Adventure 5, 2) are not murder-hobos or are willing to tone that down some, 3) understand the intricacies of this type of campaign before joining - investigation & conspiracy vs dungeon crawl & hack n slash.
For DM's, my advice is to 1) read, read, read, re-read, 2) understand the WHAT and the WHY of the conspiracy and what happens in each adventure (#2 and #4 are probably the most difficult of the first 5 to run I think), 3) clarify and communicate very well to the PCs what is going on, having Delft or someone else reiterate important details may be rail roady to some groups but I wish I had done it more often, 4) handouts are your friend, and 5) watch some TV shows like Penny Dreadful, Ripper Street, or Peaky Blinders to get a good handle on a Victorian(ish) setting and maybe shows like Sherlock or Murdoch Mysteries could help too. I was not familiar with any RPG setting other than fantasy before we started, but I've definitely developed a love for this type of campaign setting now.
