That's helpful! For comparison, here's what I ended up with after my last post:
I'll just comment on where these differ significantly.

I'll just comment on where these differ significantly.
- Putting the download button on the left helps ensure it's visible, and putting it on the right means the left margin of the page is one long line which is a little ugly. I think the left is nicer.
- I deliberately didn't want the download button to be the same color as other decorative elements to ensure it pops out more. I did change the color to something that fits the overall color scheme more (with the assistance of a color scheme tool)
- Moving the metadata and statistics up leave a blank space that I think is awkward. I've put a border above the versions list as a way to separate the version-specific and author-provided information from everything else, which is also why the archive contents are above it (right under screenshots) and reviews are below (because they come from other users).
By collapsing the archive contents by default, the top pane won't be as tall and the metadata doesn't get pushed down so far, which I think is okay without sticking it to the top near the download button (which I feel clutters the button and makes it pop out less too).
- Quote:Replaced the redundant "upload date" information (you can get it in the versions section so there's no real reason to put it right next to the download, I think) with a file size that tells you the size of the whole file you're downloading.Adding a file size makes sense, but I think it might be more useful in the top part near the download button because that's important information if you're think of clicking the download button.
I think it's still useful to have an update time in the metadata block because the version list is further down, but it could be changed to something more like "Last updated: 3 weeks ago" pretty easily- and that may be more helpful.
Quote:Moved the reviews section into the "main" section, with the screenshots and the description.I don't want reviews inside the author box (as described above), but collapsing the archive contents basically does this too, provided the versions list gets pushed below reviews.
Pushing the versions down seems a little problematic because it may be difficult to tell if you're looking at an old version of a file. I want to add a message to the top if you're not looking at the latest version if the version list is getting moved further down.
Quote:Additionally, this makes sure that long reviews don't stretch across the whole page, which is harder to read. ... Gave the review text a little bit of an indent because it looks better and is easier to read in my opinion.Margining the review body a little makes sense, and limiting the width to keep lines from getting too long also seems reasonable.
Quote:Modified the ordering of the versions section so that the oldest version is version 1 and the newest version is on the bottom.I don't like this. You usually want to go to the most recent version rather than the oldest, so they should be in reverse chronological order.
Quote:Added a header to the description section.I wasn't crazy about that, but on reflection it does seem like an improvement since it breaks the description out from the breadcrumbs better.
Quote:Added ID tags to the main headers so people can link to ex. the screenshot section by adding #screenshots to the URL. It's a small thing but it's really nice when you need it.Hardly even a styling thing, just an enhancement.
- Lightening some backgrounds seems reasonable. Indeed, the firefox accessibility checker says Cemetech Red on #bbb doesn't meet WCAG contrast guidelines. Lightening to #ccc does.
Quote:Removed "at" from the dates on the review header for consistency with posts, which don't do that.I think posts are "in the wrong" there. The review header is a single flow element so it should make sense if treated as a single sentence; removing "at" is more confusing.