It is rather interesting to me to see that V8 has been packing so many micro-optimizations and special techniques over the years that now it has become actually feasible to just start cutting back on the optimizations to have performance gains.

What all this enables is, beside having more sensible defaults, is the ability for developers who use V8 with Electron or NW.js to tweak the default behavior of the engine, catering to their application's needs. That is always good.