In set 4, most of the cards are within 3-4 spots of my rankings of them, but I have 3 major (10+ ranks) disagreements:
1. Gardens at 21 is crimially low. It's a top 10 card. Its presence totally changes the objective of the game. You now have options to go for a quick rush to piles without any real economy building, getting a bunch of cheap VP, as well as the option to build bigger and use the Gardens as an extra pile of Duchies. Either way, it significantly reduces the value of Provinces, which is a major game-changer. There's a reason it's one of the 4 pillars of the base game.
2. Conspirator at 14 seems even more insane to me. I had it at 37. Sure it provides a lot for a single card play when active, but its role isn't really that important. Most of the time, it's just adding economy to a functional engine. It doesn't add any of the actual functionality. This is something you can get out of things like Treasure Map, which no one thinks of as a good card.
3. Ironmonger at 13 seems way too high. It's at least 10, if not 20 spots too high. Ironmonger can only be reasonbly reliable as a village with strong trashing (or some way of controlling your deck top), otherwise there's too a great a chance that you don't hit an action. It comes with the nice side-effect of being a lab or sifting peddler when you miss, but most of the time you'd rather just have the village. It is also usuable in decks without strong trashing, but not as a village. In this case, it's kind of a single-card-sifting peddler or lab, which sounds good, but a peddler or lab in an untrashed deck really isn't anything to write home about. It's something you'll gladly buy for $4, but not something that's a huge impact card.