Based on the last round of feedback, here is another round:
If something isn’t being shown, you can assume that it isn’t really up for discussion anymore. (Except perhaps for color schemes, which this round may change.)
As usual, hit us with your comments, but do it soon as we’re iterating faster now.
Thanks!
MetaBrainz Blog 
First off, I highly doubt all the comments from “the last round of feedback” has been accounted for, considering there were only 40 minutes between the last comment there and this post.
Anyway:
(I also commented on this on the previous post.)
1) Much prefer the mixed case! Thank you for that, bitmap! I’m not sure I like how the font has the dots of the i and top of the k higher than the capital M and B.
2) Much prefer page 1 (one line of text, regular placement) to page 2 and page 3.
3) I prefer the MusicBrainz-over-Picard rather than the Music-over-Brainz-next-to-Picard. No strong preference towards colour, but I think I’m leaning slightly towards to light blue. I would still like to see how it would look with the tag on the right-hand side and the “Music” from “MusicBrainz” on the left, as commented on the previous post.
4) I, personally, like the brown BB logo. The k looks a bit off to me, as per 1) though. Also, I don’t like how the lines and outline of the book doesn’t match up with the brain-lines on the right.
I prefer the logo with more branches on the right, as opposed to the two-branch version on the “Smaller footprint” page (or is that for smaller versions of the logos? If so, it’s fine).
On the “Variation” page, I don’t care for the dot on the bottom of the “i”. Maybe this could be rescued if the lower-case letters on each side were aligned (i.e., so that the tops of “us_cBrainz” were aligned, with the “B” and second “i” protruding below the “c”).
I like both Picard’s tag, and BookBrainz’s book. All of the color combinations look good, though if I had to pick favorites, I’d probably choose the topmost one for Picard, and the second one for BookBrainz.
Maybe it’s me, but something about the font says “video game”. This is Roboto Condensed, yes? May I suggest Oswald or Open Sans Condensed, which look slightly more businesslike?
I like the dark green bookbrainz, it shows up a bit better than the light green. I am a fan of the red Picard icon.
I still think there should be a bit of a top to bottom gradient to pull the eye along.
I like the logo, but don’t like the wordmark very much as it is. The font spacing seems irregular. I’d prefer the normal text orientation, not the playfully mirrored version.
I don’t have too much feedback at this stage, looking good, but if you go lower case the logo text really has to be single-line. Otherwise I think it visually looks ‘wobbly’ – because of the ‘i’s but also the bottom of the ‘u’ and the ‘a’.
Lower case looks warmer, upper case looks more ‘tech’.
I like the BookBrainz (exciting!) logo without the writing on the page, especially next to the Picard logo.
Colours I think you guys should probably just make executive decisions, I’m not sure if a family of colours could be decided on by committee… Everyone’s going to like some and hate some.
Bright red/ a brighter colour looks slightly out of place for Picard, but maybe that reflects its status as an application rather than a DB, compared with the rest?
The mixed case is nice, but the capital B seems to be too small, and the letters seem to “dance” a bit. The lower case K seems to be excessively tall as well.
The inverted “i” seems out of place (especially in the cases where “Music” above “Brainz”). It strikes me as a little “unprofessional” as well.
I like the red tag for Picard. As suggested elsewhere, it may make sense to swap the icon sides around (to have the brain on the Brainz side and the tag on the Picard side).
I like all but the middle colors for BB; the brown seems the most apt, since it evokes wood/leather, both of which tie in to books.
Apologies for the late comment.
I like the new design, though I prefer the existing (historical) typeface over the new one.