I forget if I've brought this up somewhere before, but edit conflicts are an issue with this tool that needs to be resolved before it goes out of beta. When you've been writing out a comment and someone else edits the article, before when you tried to click publish you'd get the edit conflict screen. Sometimes that'd be annoying, but other times it'd allow you to adjust what you write to take in their comment, or at least to add the edit conflict template to your comment to indicate that you wrote it without knowledge of theirs. However, the new reply tool just powers through and posts the comment, without any tag.
This could result in some awkward social situations (let me know if you're having trouble imagining them and I'd be happy to concoct examples). I'd recommend that the tool either learn to apply the EC template or display a heads up confirmation that lets you read the new comment before deciding to publish. Cheers,