I'm a relatively new web dev and I've been quite happy with Firefox's Web Dev tools. What does Chrome's dev tools give someone that Firefox's doesn't? I can edit css on the fly, see where a css rule is being overwritten, debug javascript, etc.
I use FF but Chrome's dev tools have a lot more going for it including memory profiling and performance tools. On the other hand, Chrome's network panel is awful and it's a chore to see the domains and full URLs involved.