There have been many things said about these four lands, and all I have to say about them is that they are card advantage. And yes, this is a space filling post. Boros Garrison and Selesnya Sanctuary might seem to wreck the tempo of the two guilds, but I'm quite certain that the Golgari and Dimir guilds don't take the same amount of tempo damage from Dimir Aqueduct and Golgari Rot Farm due to the slower game plans that these two guilds employ.
However, these lands still do an excellent job of colour-fixing, and should not be omitted in any casual deck looking for a good way to increase their decks' consistency to run smoothly. Running these lands might even warrant you running less lands in your deck since one of these lands can produce two mana once untapped, which means you have to have less lands to get things done!
These lands allow you to return a land back to your hand, which could come in handy for lands that come into play with something, such as Tendo Ice Bridge. Some people might think the lands are overcosted, but when you're playing with them in the right deck for the right reasons, you'll find the cost to be minimal compared to what painlands might cost you in the game or in real life.
What comes to mind immediately is anything that triggers well over multiple lands plays like Vinelasher Kudzu. Two of these lands could very well be your ticket to a huge Kudzu, but likelihood is if you're playing Kudzu, you'll be putting it together with a Meloku the Clouded Mirror, which would very welll generate enough of everything good to win.