It's the same at slashdot, non? Seems to work well for them.

Personally I think comments on comments which have a lot of diggs the comment they are replying to should be kept open.

Perosnally I find Slashdot annoyingly slowly

Actually, I completely dislike Slashdot's comment system. I've heard from people who like it, so it seems to be a matter of taste. But I find it so confusing that I pretty much never read the comments, or only glance over them. That being said, I've switched from Slashdot to Digg so I don't go there often anymore.

In order to participate in a discussion I think it's important that every user gets a chance to understand how it evolved – even to understand which previous comments were getting flamed because they are wrong etc. (so you don't repeat the previous errors in new comments). I really liked the old Digg comment system, simply because it was so easy to understand. However, letting people get positive votes does make some sense, for one thing it's fun, and it also gives commenters the incentive to write longer, more thoughtful comments (something Digg isn't exactly famous for). The new Digg comments threading also makes some sense.

Slashdot and Digg are seriously competing with each other at the moment. Both are trying to implement new features that will gain some of the other's user base.

On both sites, the default view can show replies to undisplayed comments.

Merlin from CoComments is building a digg thingy too.. its the reverserve happening there ..they can dig they story from their comments..

"Just click on the bookmarklet before posting a comment on digg. Then your comment will automatically added to your conversation in cocomment."

http://www.cocomment.com/comments/Merlin

its a cross over of technology happening ..literally!! :)-

btw.. coComments is still deep beta

I like the new digg comments system!

I prefer Reddit's system, where comments are never hidden, but they get moved up and down the list depending on how highly they're rated.

I hate system's like Shii describes as someone often replies to someone who is below them, which is totally confusing. IMO you need either strictly chronological flat style or a tree.

I also can't stand the hidden comment system on slashdot... I just don't know a "best" way to do it. but once you hide comments, and start seeing people reply to something that you have not even seen... it gets confusing... as soon as that happens, I generally leave the page :)

I have noticed that often (at least in the comments that get modded up) slashdot users quote the relevant part of the comment they're replying to.

German Heise, a sort of Slashdot, sorts comments into threads (you see only the title of the thread) and it sorts threads onto pages. You can then expand a thread. An example:
http://www.heise.de/newsticker/foren/go.shtml?list=1&forum_id=94329

I *love* the new comment system. The old one would completely hide poorly rated comments and allowed people to basically censor the comments section. I didn't even know comments were hidden at all until I'd been reading dig for a couple of weeks. This system is a *lot* better. I wish the threading could be nested further, that gets confusing sometimes. I'm one of "those people" who think slashdot's comment system is perfect. With a system that big, you're going to get sammy and stupid comments, so you have to have some way of hiding irrelevant ones. I've also noticed diggs system is dynamic if you're logged in – for instance, my threshold is -4 diggs because I've manually shown comments in that area and then dugg them. it's very clever. Now all they need is pagination so popular stories don't crash Firefox.

What digg *really* needs to do is partner up with one of those personalized news services. They know exactly what i like to read--i always digg it. Now its time to cater to the long tail.

No matter what Digg does to it's comment system, Slashdot will still be lightyears better. The constant spam on Digg is more than a slight annoyance.

I'm personally very familiar with a web service that abuses Digg regularly. They add items themselves and then actively (and specifically) encourage their large user base to digg these items. It seems like every week there's what essentially amounts to an advertisement for this company on the top of the digg pile.

And I'm not knocking the web service. Digg allows this to go on. Digg's fault. That doesn't happen on Slashdot.

And (on a related subject) I have to put in a plug for http://del.icio.us . I'd rather see the latest delicious faves than the latest Digg faves any day.

http://del.icio.us/tag/

I don't like the new system, because of the slow rendering / loading of the pages.