Better resistance to magnetism, better rate stability, and greater efficiency in energy delivery to the balance are probably the three main basic benefits of all these high tech materials and methods, and they're all inarguably beneficial to consumers. And the diversity of approaches means watch buyers are spoiled for choice. But despite all that, I still find silicon hard to swallow, and so do other watch lovers, and I'm not entirely sure it's a rational decision. It's definitely true that silicon balance springs won't be replaceable if for some reason silicon fabrication becomes outdated, or we bomb ourselves back to the Stone Age (or the Iron Age at least, let's say) but short of imagining such post-apocalyptic scenarios, it's a little hard to take seriously the idea that no one's going to be able to make a silicon balance spring in a hundred years.

Silicon doesn't sit right with many of us, but the fact is, Nivarox balance springs are the result of highly technical industrial processes as well, and they certainly don't lend themselves to easy replacement by a lone watchmaker at his bench in some future scenario where making iron-nickel-beryllium-what have you balance spring alloys becomes a thing of the past. It is certainly true that in watchmaking, the inability to easily reproduce parts made of exotic materials, or with exotic methods, or both, can permanently turn a watch into an inert object; just ask anyone who's ever wanted an Accutron watch repaired. The problem there however, is not that we couldn't in principle make Accutron index wheels if we wanted to; the problem is that it's not worth it.