My fiance and I just rewatched Doukyusei! Still love it as much as I did the first time around. I have a few thoughts on Aniplex's BD release of it.
The set itself surprised me a bit; it's much more in line with Aniplex's older releases. This is a good thing, since that's the quality I expect out of them. The last release I bought from them was Koimonogatari, which let me down a bit with its flimsy case. Doukyusei on the other hand uses a rigid case, just like their Fate/Zero releases. Apart from the BD itself, it comes with a cute set of postcards and a small artbook. The artbook itself was nicer than I expected, as it also includes an interview with the mangaka, and a new manga chapter. While it's not a big book by any means, it's a lot thicker than the flimsy artbook that Koimonogatari came with.
As for the disk itself, it's simply great. Out of all the Aniplex releases I own, this one by far looks the best. The film is absolutely beautiful, and the image quality is amazingly clear. A small word of warning though; there's a lot of really bright white in the film, so watching this in a darkened room may hurt your eyes at times, especially when it switches from nighttime scenes to daytime ones. I learned that the hard way.