A small detail but I haven't seen it discussed yet. I really enjoy the new alerts. The subtle economy alerts are great for example. "you are wasting metal". "you are wasting a lot of metal" (or something like that). "Your commander has entered a new biome". All these new announcements sound great and really make the game more intuitive.
wreckage_health_frac for basic units is 0.7, which I believe is about 40%. This will be reduced by overkill and splash damage, and increased by reclaim error.