Geriatric hedgehog
Pokémon Master
Ah, just had to scroll back to catch up on this... This may throw a spanner in my UK version ambitions...Going by the Funimation streams (which evidently came true for CLANNAD), the K-On! discs Manga currently have (atm) are the old Bandai Entertainment masters for Season 1 (which were released in four parts, hence 4 Blu-ray discs) and the old Sentai Filmworks collection disc masters for Season 2 (which received two parts, hence 4 Blu-ray discs also) as well as the old Sentai release for K-On! the Movie (the same one Manga released on Blu-ray years ago).
Sentai are known in recent years for basically improving their releases for every re-release. The Ultimate Collection release, which is 7 discs in total, improves on most of the issues (I believe there's an audio issue in Season 2 that wasn't fixed in the re-author but everything else was improved for the better). Also remember those K-On! shorts that were initially exclusive to the Japanese Blu-ray box? That's included in the Ultimate Collection release.