I once summed up my judgement of RationalWiki as "Rationality is their flag, not their method." I have paid it no attention since forming that opinion. When I last looked at it, their method was sneering, every article was negative, there was no rational content, and no new ideas. It is not worth even the minutes of my time it would take to look again and see if the leopard has changed its spots.
If I remember correctly, rationalwiki came into being as a response to Conservapedia, which is the American religious right's response to Wikipedia. The main issues originally at play were scientific: climate change, evolution, and the origin of the universe. Conservatives who disagreed with the consensus formed their own wiki.
People on the left formed rationalwiki to tit-for-tat the right. Called it rationalwiki because the denial of scientific consensus was irrational; I don't think the name had any connection whatsoever to the rationality blogosphere.
Rationalwiki admits to taking a "snarky point of view," which to me is an admission that documenting truth is not their primary aim.
It gets mentioned around here, usually in a negative light, but I don't think I've ever come across it except when someone here complains or asks about it. It's not early in any search results, and nobody I follow or correspond with links to it. It's just one of billions of websites that have no impact on anything.
From what little I've seen, it seems more community- and popular-culture-focused than LessWrong is, and the approach has more editorial slant than LW Wiki. I don't see a lot of overlap between here and there.
I don't think, unless you have some unstated reason to, you need to have any thoughts on it.
The site seems less focused on providing as accurate information as possible and more focused on shining a particular light on it's topics. This can also be seen in the writing style, it's more casual and pointed than e.g. Wikipedia.
I personally think if you take the above into consideration, rationalwiki can be a good way to get some pointers into how a topic is percieved from a certain point of view, but you have to accept that you'll only get one perspective.
They aren't rationalists per se, and don't seem to overall have a high opinion of rats (though they're also willing to paint a better picture of e.g. Scott Alexander than e.g. r/SneerClub paints, so it's probably best to not confuse the two), and they're willing to get personal and ad their hominems.
However, while I'd give them less credence than Wikipedia (which has issues of its own, as we're all aware), that doesn't mean that I ignore it entirely. Maybe it's because I grew up in a cult, but RatWiki is really nice to visit every now and then, for much the same reason that I still visit r/exmormon every now and then. Also, it keeps a better list of cranks and scoundrels (and their cons and scandals) than Wikipedia, so I also use it every now and again as a(n initial) resource whenever my parents mention some person or thing which I'm pretty sure is bullshit just by the sound of it.
I think that the ideal community size (the regime at which positive network effects clearly dominate negative effects) is much larger for a wiki than for a forum like here. Thus, though I don't have experience with RationalWiki, my prior would be to be skeptical of its value.