|Howl's Moving Castle: Special Edition (Hauru No Ugoku Shiro) (Studio Ghibli||R4|
There doesn't appear to be 'new' Special Editions in R1 or the UK. So the comparison below is relevant from the Limited Edition.
The Region 4 appears to be identical in content and transfer quality to the UK Region 2 release.
The US Region 1 has all of the extras present on the Region 4 plus a short featurette on the making of the English-language dub. From screen caps available on the internet it looks to have a marginally less sharp, less detailed video transfer than the Region 4, and also appears to be slightly stretched vertically (though that could be a result of the screen capture, not reflective of the actual transfer).
The four-disc Japanese Region 2 Special Edition release is noticeably windowboxed on all sides and the video transfer seems to be markedly inferior to the Region 4. Each of the first two discs has the film complete. Disc one has Japanese soundtracks with DTS ES Matrix and Dolby Digital 2.0 tracks but does not have English subtitles. The second disc has a choice of various language soundtracks in stereo only and English subtitles. Discs three and four have a variety of extras, including all of the extras on the Region 4 but without English subtitles.