Windows Explorer crashes for me about ~3 times a day at work, and takes down the taskbar with it, so not sure about more stable. I don't use Nautilus though because it's pretty bare bones compared to Dolphin. Also:

> These super-indexed desktop linux search functions are also dog slow

Baloo-indexed KRunner on Plasma is instant. I index my entire home folder, including hidden files, and I can substring search with imperceptible latency. I can't speak to other search implementations, but yes KRunner + Baloo is much faster than grep.