So I decided to take a look at LiveJournal's RSS support this morning. It works like this. As a paid LiveJournal user you are able to subscribe to a feed. You give it a name and the url to the RSS feed. Once this happens the feed is pretty much out of your control. You can't do anything with it. It gets a generic template and to other LJ users can appear just like another user in their friends list (You can see how it does it here). Judging from some of my past experiences with some of their site I probably shouldn't have expected more from them than I got. Though I really only have one real gripe (well, two if you include that I hate how they format the posts).
My biggest gripe about it is how they handle comments. If your blog is subscribed to by someone on LJ, you may have a whole other set of comments for your blog over there that you don't know about. Because LJ has comments built into it, any feed that shows up on LJ has a link to comments on the posts. This is where I start to not like how they aggregate RSS feeds. Part of RSS is the <comments> item. This contains a URL where comments can be made on a post. If it is there you should use that for the comments link. That's what it is there for. I'd probably even argue that if there isn't a comments link LJ shouldn't let people comment. It gets more confusing too. If you look at some of the popular feeds there is more than one feed for some of the blogs (Wil Wheaton's for example). And each of those has comments on them.
LiveJournal also has an RSS feed that can be subscribed to for any LJ user. Just add /rss onto the end of their URL. So http://www.livejournal.com/~gblake/ becomes http://www.livejournal.com/users/gblake/rss/. LJ actually does a pretty good job here. In fact, they even support the use of <comments>. Just in case anyone reading the feed wants to read and post comments. How nice considering they don't pay attention to this tag when publishing other people's feeds.
So, they get it about half right. LiveJournal gets bigtime points for providing feeds of their users journals. But their support for subscribing to remote feeds has issues that annoy me greatly. It just feels kind of unfinished or not real polished to me. Which, unfortunately, is how a lot of things on LiveJournal feel to me.