I don't know how to say this without sounding rude, but the Future of Humanity Institute and Nick Bostrom give a formal/professional appearance that the SIAI and Eliezer Yudkowsky lack.
There's some truth to that - but I can't say I am particularly sold on the FHI either. Yudkowsky seems less deluded about brain emulation than they are. Both organisations are basically doom-mongering. Doom-mongers are not known for their sanity or even-headedness:
History is peppered with false prognostications of imminent doom. Blustering doomsayers are harmful: Not only do they cause unnecessary fear and disturbance, but worse: they deplete our responsiveness and make even sensible efforts to understand or reduce existential risk look silly by association.
It seems difficult to study this subject and remain objective. Those organisations that have tried so far have mostly exaggerated the prospects for the end of the world. They form from those who think the end of the world is more likely than most, associate with others with the same mindset, and their funding often depends on how convincing and dramatic picture of DOOM they can paint. The results tend to lead to something of a credibility gap.
In what way do you consider them to be deluded about brain emulation?
While I agree that in general, organizations have an incentive to doom-monger in order to increase their funding, I'm not so sure this applies to FHI. They're an academic department associated with a major university. Presumably their funding is more tied to their academic accomplishments, and academics tend to look down on excessive doom-mongering.
Basically this: "Eliezer Yudkowsky writes and pretends he's an AI researcher but probably hasn't written so much as an Eliza bot."
While the Eliezer S. Yudkowsky site has lots of divulgation articles and his work on rationality is of indisputable value, I find myself at a loss when I want to respond to this. Which frustrates me very much.
So, to avoid this sort of situation in the future, I have to ask: What did the man, Eliezer S. Yudkowsky, actually accomplish in his own field?
Please don't downvote the hell out of me, I'm just trying to create a future reference for this sort of annoyance.