Yosuga no Sora

Hm, so does this mean you don't plan to read the VN? I think if you have any plans to read a VN you should always read it before watching the anime adaptation because the adaptation will cut things out or shuffle things around to fit the format. VNs sometimes have ero content that the adaptation can't have, too, so that's something missing.
I see the anime adaptation as a great way to experience it again and see the characters in motion, but at the same time it lessens the the experience of the VN if you read the VN afterwards. Sometimes you get lucky and the anime adaptation adds a bunch of new stuff, which was the case for Utawarerumono 2! It's almost more like a bonus disc or bonus version of the VN! (though it did gloss over things at the same time)