Jeff locked the testing thread three minutes before I finished this post. Hopefully it's still relevant:
On audio clips, I like Jeff's disappearing musical note icon method and I'd suggest it go next to the other icons in the top right. I do not like the audio control bar under or above any caption as I feel that cuts into the image size/viewing area.
As I said, I could argue that both ways. If the audio clip consists of a nice tune, and the MP3 is set at a reasonable volume, the "disappearing note" method is fine. But if the audio clip is some kind of narration, you might want to have the control bar more directly accessible, so that you can quickly make the album creator STFU.
(NB: on released version, I see this has been addressed.)
As for downloading originals, it appears one (he/she/it) still needs to check TWO boxes (under Lightbox and under Images. Jeff offered a nice solution to address that.
Yes, looks like that has been nicely simplified. Included original (along with the scaled image), you get the download button.
(he/she/it, to or for, by with or from, everybody - omnibus pronouns/prepositions)