I'm rather glad you made this article, old sport, as it made me realize that I was treating this particular debate as an "arguments as soldiers" issue, wherein I must crush all opposing arguments and may never betray an ally. This was, of course, incorrect thinking, and so I'm glad I don't think that way anymore.

But looking at all the comments so far, it doesn't appear that there are any strong objections to life extension technology. There are the expected problems and the unexpected problems, but the same could easily be said of all sorts of tragedy removals that technological progress has brought us over this time. None of the ideas brought up in this post even attempt (so far as I can tell) to argue against at least doing research on life-extension, and, as others have brought up, this near-impossibility of existential risk from such technologies make the AGI analogy extremely weak.

So, good thing to bring up. But for the most part, we're done here.