Needless to say, the video quality of the BluRay disks is stunning. As expected, the animation is first-rate, and leaves little to be desired visually. Brilliant colours and production design make the viewing experience a real pleasure.Unlike the OST CD's,the sound quality of both the DVD and BluRay disks is excellent, with plenty of acoustic headroom for louder passages without clipping or distortion. The mix between the background music and dialogue is well done. A good sound system is a must for full enjoyment of these discs. Both the English and Japanese soundtracks are excellent - you'll likely want to watch both versions.Although the English and Japanese VA's (voice actors) are different people, the voices are well matched, so that either version is quite believable. Listening to the English language sound track while watching the English subtitles shows that there is some difference between the translations and the spoken VA words. Nevertheless, the English sound track is very logical, even though there are some occasional word substitutions from the Japanese.All in all, this production is well done, and leaves the viewer wishing for another season. You will watch this more than once!