Having 2 or 3 Cartographers in your deck is just so good. The reordering ability that Cartographer has is why Apothecary is so darn good, and you also get to discard? That's good! I don't like Cartographer much, but it's a solid card, and should be considered on every board.
I'll say this, and it's worth repeating over and over: Cycling is good. It's better in the early game, and it does get worse when you start greening, but overall, cycling is a big deal. This is why Warehouse is so great. This is why Apothecary is great. It's not just the Copper draw, it's the cycling that comes out of it all too. Discarding dead cards with Cartographer prevents bad cards from entering your hand, but it also lets you cycle faster. This cannot be understated.
This is why towards an end of a shuffle, you might just discard all your Coppers and Silvers and that one Hamlet with Cartographer, just to get faster cycling. It's highly situational, of course.
(Awaclus case: You have another draw card, so you'd leave the Hamlet and Silver, draw the Hamlet and the Silver for extra economy. If you can do that, great. Just making a general example about cycling and Cartographer's discard ability.)