Hi,
we've experienced the next issue in our most recent project (and first one hosting assets other than model files in s3). The copy times for the files were pretty good before release. No problem here, the plugin works wonderfully.
Once online, there are a few paperclip'd models that upload to the same bucket, and create files with a url like "/id/class/size/image.jpg", so if you were to log into the bucket with transmit you'd find lots of directories straight in the root. We're aware this might not be the best practice, but there was a good reason at some point for this.
Anyway, now that there's about 2000 items of these models, the copy times has multiplied by about 30, going from 30 seconds (slow but ok) to 15mins (not so ok).
Tried to understand the code and see what happened but it's completely out of my league.
Don't know if this is an issue really, or the problem might be something else, but I thought I'd at least share.
Cheers for the great plugin