When I debug in firefox, I use the native debugger. Firebug takes a long time to start up. Am I missing out, or are the two similar at this point?
They're basically the same, except the native debugger--like you said--is faster. I love Firefox, but I've switched to Chrome for the dev tools and overall speed.
Firebug pre-dated (and heavily inspired) the native debugger, so the GP is probably intending to suggest doing without either of them.