I'm a web-developer and i mainly use google chrome - on windows 7
Reason for me using chrome, is because of inspect element. (The script debugging side of it)
And since its quite fast, its easier to quickly reload after i edit php code.
The Web Developer extension is pretty helpful, but i do like the firefox one better. But really, it could be better if it had more time (chrome is still new after all).
As for the flash crash, i've never had that issue, except when resizing a window with a huge flash element as the background or anywhere else. And it would just memory leak until i close the tab. (odd?)
For caching, its about 3 clicks in firefox to clear the cache, and 5 for chrome. I've gotten used to doing it in chrome, but it still bugs me some times.