The german hdtv transport stream I used as the main source for AOTC is 16-17gb so yeah, IMHO the difference between a 22gb version and a 50gb version wouldn't be noticable to the eye.

ROTS I used the blu-ray as the main source but there isn't really much grain in that release so i'd expect the difference to be barely noticable between a 22gb and 50 gb version.

TPM had the additional grain that I added which is very bitrate hungry so when I did tests comparing the 22gb bitrate to the 50gb bitrate, I could quite clearly see that the 50gb bitrate reproduced the grain structure more faithfully so I felt it was worthwhile creating a 50gb release.