Qutebrowser is also worth checking out. I haven't really given it a full blown test drive yet, but it's certainly less bloated than Firefox and Chrome, and has Vim-like keybindings.
I use VimFx which doesn’t modify the browser chrome as much as Pentadactyl (apparently). It simply provides lots of convenient Vim-like keyboard shortcuts. I also use the ItsAllText! extension with GVim configured for editing text boxes. I'm not aware of any issues that either have with the new extension architecture.
