We have discussed the lack of commenting moderation options - but that's just a small part of what you don't get.
This blog owner is used to the array of comment settings, that seem natural, to somebody using Blogger comments.Under Settings, then Posts and comments, I don't have the same choices as shown.
With Google+ comments, you get one setting, under "Posts and comments" - Comments.
Everything else is part of Google+, and stream behaviour.
Anybody who can see the blog can publish a comment.
Besides the lack of moderation options, the lack of control over who can comment can be disconcerting. With Google+ Comments, anybody, who has an Exciting Google+ account, can comment - just as in the Google+ stream, anybody can post anything they wish.
Unless you, the blog owner, are in a Circle that's addressed by a commenter, you won't even see a non Public comment - even if your blog is mentioned. This leads to more confusion.
Why does the comment count go up for this post - even with no comments visible?
Google+ will count comments that you may not get to see. This too can be disconcerting. Anybody can comment, on your blog - and you can't see the comments. Comment moderation is left to the people who can see the comments.
Google+ Comments only work for public blogs.
But there's a more intriguing oddity. We are told to use Google+ for distribution of private blog posts - but you cannot use Google+ Comments on a private blog.
Google+ hosted comments only work, with public blogs. With a private blog, you use Google+ to distribute the posts - but you can only use Blogger hosted comments.
Since automatic post sharing only works for Public shares, you have to manually share each post - so you can select the appropriate Circles to view each individual post.
If you have a private blog, your readers can discuss your blog posts, in their streams - but nothing will show up on the blog. And, they can view the blog - and possibly comment there - but nothing will show up in their streams.