The only downside of this approach I can see is that an upload-triggered Unfriendly singularity may cause more suffering than an Unfriendly AI singularity; sociopaths may be presumed to have more interest in torture of people than a paperclip-optimizing AI would have.

What about those of us who would prefer indefinite human-directed torture to instantaneous cessation of existence? I have no personal plans to explore masochism in that sort of depth, particularly in a context without the generally-accepted safety measures, but it's not the worst thing I can imagine. I'd find ways to deal with it, in the same sense that if I were stranded on a desert island I would be more willing to gag down whatever noxious variety of canned fermented fish was available, and eventually learn to like it, rather than starve to death.