I think EA is at its best when it takes the high epistemic standards of LW and applies them to altruistic goals. I see the divergence growing, and that worries me.

Personally, I'm not a fan of LessWrong's thinking style, writing style, or intellectual products. As such, I think  EA would be better off with less LW influence in the near-medium term. 
However, I'm not familiar enough with EA's intellectual history to judge how useful LW was to it; I certainly can't predict EA's intellectual future. It seems possible that future exchange would be useful, if only for viewpoint diversity. On balance though I'd lean against heavy exchange.

I'm in favor of a clear separation between the forums. They are made for different audiences and not everything that is meant for one is meant for the other. As somebody who writes some pieces that are meant for both audiences, the cross posting feature is somewhat convenient for me (but not hugely so; I can just copy and paste). And as a reader, sometimes it's nice to see a post is cross posted so that I can go see the comments on the other forum.

I'd be interested to see how much the easy cross posting has increased the number of cross posts, and if so what kinds of posts are now more likely to be cross posted. This seems like an analysis the forum team could do and is harder to do anecdotally.

The EA Forum and LessWrong have some of the best technical infrastructure on the internet, and I think the EA Forum derives huge benefit from that. However, it does make me a little uneasy that it's made by the Lightcone team, who are in charge of LessWrong. I like the people on that team, but I expect probably some decisions that are good for LessWrong but not so good for the EA Forum might just end up propagating here by default. This is just a suspicion; I don't have any particular examples.

A lot of separation does exist. LessWrong posts are moderated pretty differently, the commenter audiences are often very different, and the types of posts are mostly different. So the connection as is isn't currently a huge concern of mine.

Crossposting has been a huge win in my opinion.

It used to be what you did was post on one site and then manually crosspost to the other. This was annoying and somewhat error prone and you had to setup the links yourself by editing at least one post after it was published.

Automatic crossposting eliminates that mess, and it adds the nice feature of letting you know if there's comments on the other site (since you don't want to read the same thing twice but you might want to know about the conversation on the other site).

The feature is also fairly easy to ignore if you don't like the other site, and there's not a ton of cross posts so it's not generating a lot of noise.

I guess if you don't like Less Wrong it might feel annoying to see Less Wrong content on EAF, but honestly you were going to see it anyway, it just would have been less clearly labeled.

As a datum from the LessWrong side as a moderator, when the crossposting was first implemented, initially there were a bunch of crossposts that weren't doing well (from a karma perspective) and seemed to be making the site worse. To address this, we added a requirement that to crosspost from EAF to LW, you need 100 karma on LW. I believe the karma requirement is symmetrical: in order to crosspost an LW post onto EAF, you need 100 EAF karma

The theory being, a bit of karma shows that you probably have some familiarity with the crosspost-destination site culture, and probably aren't just crossposting out of a vague sense of wanting to maximize your post's engagement.  I don't think it's been a problem (in the EAF->LW crossposting direction) since.

I think the current arms-length community interaction is good, but mostly because I'm scared EAs are going to do something crazy which destroys the movement, and that Lesswrongers will then be necessary to start another spinoff movement which fills the altruistic gap. If Lesswrong is too close to EA, then EA may take down Lesswrong with it.

Lesswrongers seem far less liable to play with metaphorical fire than EAs, given less funding, better epistemics, less overall agency, and fewer participants.

Pro starting messy discussions around things that are elephants in rooms (not all of them, but on the margin, and this one seems good!)

My gut feeling is that LessWrong is cringe and the heavy link to the Effective Altruism forum is making the forum cringe.

Trying to explain this feeling I'd say some features I don't like are:

• Ignoring emotional responses and optics in favour of pure open dialogue. Feels very New Atheist.
• The long pieces of independent research that are extremely difficult to independently verify and which often defer to other pieces of difficult-to-verify independent research.
• Heavy use of expected value calculations rather than emphasising the uncertainty and cluelessness around a lot of our numbers.
• The more-karma-more-votes system that encourages an echo chamber.