I've just moved from FireFox and it's all going well so far. The only thing I miss in autocomplete function is giving autocomplete suggestions when not starting from the string, my english is not good enough to describe it so will give a little example:

1. I have a text field when I put some url like http://opera.com
2. When I type "opera" in that field, autocomplete suggestion is not coming up, it only comes up when I start with "http:"
3. So autocomplete should search for the typed in string.

Just my 2 cents.