NATSUHIME is the successor to the now defunct GELATIN Magazine, offering basically exactly the same thing but with more nudity and racy comics. Judging from this first volume, it seems like it's going to head even more in that direction; half of the comics feel like they were intended for the June issue of GELATIN that was canceled at the last minute, and just don't fit the new more adult theme.
Soundgirl DUO is the commercial realization of the previously reviewed doujinshi Soundgirl - Onkyou Shoujo-. There is no illustration overlap between the two books, but several of the artists featured in the original book contribute at least one illustration each to Soundgirl DUO. This second book came out November 30th and retails for ￥1800.