I usually like it... Rated 4 out of 5 stars
Lately it's switched to searching Amazon only. I've tried to change it back to Google, and the little Google icon shows up in the address bar, but it still searches Amazon which doesn't help me at all. It's great when it works, but behaving this way it's useless and I don't know how to fix it.
Edit: Fixed it a few days ago. Deleting Amazon as an option for search seems to have convinced it to go back to using Google. But then I updated and it did the annoying >> thing. To fix it, try going to about:config and changing browser.urlbar.autoFill to false. Seems to have worked for me.