Why should it make copying, pasting, or editing URLs more difficult? Right now in stable Chrome, you click once on the URL bar and it selects the entire URL. Then you can Ctrl-C to copy, Ctrl-V to paste, or click again to put the cursor in a specific place to edit it. That shouldn't be any different with this new Chrome feature they're testing.
The F6 functionality is the reason I welcome this, Chromium devs aren't really taking control from us more tech savvy users, they're making it easier for regular users to spot the relevant part of a URL.
I already use F6 for all interaction with the omnibar as it is. Also, I'm not sure which browser it was (Opera or Firefox), but I distinctly recall either of those a few years ago having the exact same functionality discussed here, where only the domain was shown unless the URL field was active.
