At the time I read the story, Economics 2.0 and its effect on humans that installed the upgrade paralleled with some stuff I had read about sociopathic behavior. Stross later wrote about the same ideas in Rule 34.
I have mild tinnitus, and I don’t really notice it at all when my hearing aids are in. (Phillips, got them at Costco) Sadly, it’s a lot more noticeable once I take them out. I am still waiting for that electrostimulation therapy I read about a few years ago to pan out.
I can speak to this - the main variations are in the kind of butter you use. Using salted, unsalted, or margarine result in similar yet different cookies. I personally use unsalted and feel like it creates the most “cookie” like experience. Flour brand and texture also makes a difference. You will get a very different result based on using the store brand vs (for example) King Arthur flour.