It might be hard at first to tell the difference, so I'm going to have to use some examples. I'd ask that you try and suspend any emotional reactions you have to the examples I chose and just look at which approach seems more rational.

Bullshit. You aren't providing an example because it is "hard to tell the difference at first". You started with an intent to associate SIAI with self delusion and then tried to find a way to package it as some kind of rationality related general point.

Contrast this with the Singularity Institute. A skeptic might well ask whether the Singularity is actually going to occur. Well, the SIAI FAQ addresses this, but only to summarily dismiss a couple objections in a cursory paragraph (that evades most of the force of the objections). And that's the closest the FAQ gets to any sort of skepticism, the rest of it is just a straight and confident summary that tries to persuade you of SIAI beliefs.

The FAQ on the website is not the place to signal humility and argue against your own conclusions. All that would demonstrate is naivety and incompetence. You are demanding something that should not exist. This isn't to say that there aren't valid criticisms to be made of SIAI and their FAQ. You just haven't made them.

Which attitude seems more like a serious scientist? Which seems more like Uri Geller?

Am I the only person who is outright nauseated by the quality of reasoning in these recent mud-slinging posts by aaronsw? What I see is a hastily selected bottom line along the lines of "SingInst sux" or perhaps "SingInst folks are too arrogant" then whatever hastily conceived rhetoric he can think of to support it. The problem isn't in the conclusions---it is that the arguments used either don't support or outright undermine the conclusion.

Competent criticism is encouraged. But the mere fact that a post is intended to be critical or 'cynical' isn't sufficient. It needs to meet some kind of minimum intellectual standard too. If it did not represent an appeal to the second-order-contrarians and was evaluated based on actual content this post would probably end up mildly negative, even in the discussion section.