I'm on both. HN has a more diverse community and array of content. There's just a ton of stuff on here. That can up the noise for many people but one must simply filter it in their head more effectively. I only click on a few links on the front page with occasionally looking at New and 2nd-3rd pages to see if readers and I would benefit from me bumping one up.

Now, Lobste.rs is different. They're a small community with a narrower focus on mostly tech stuff. They have relatively low noise with a preference for deeper insight on tech. You'll see more writeups on algorithms than product releases for instance. They also have an open-source website and open moderation log. A bit radical on occasion like where owner JCS just got rid of downvotes to experiment if upvote-only would keep quality without total censorship.

Definitely check out the articles over there on top of the ones here. The comments especially as people often say something there that someone here overlooked or vice versa.