Please understand that browser integration is the Achilles' Heel of password managers. While you get the convenience of autofill, you're also bringing access to your password database into the browser's attack surface. Bugs in the browser sandbox or improper extension implementations can allow rogue sites to get the goods. There have been multiple instances of major password manager extensions leaking secrets just in the last year.

Copying and pasting may be annoying, but it's much safer, especially if you use a program that will autoclear your clipboard for you (KeePass 2 does this after 12 seconds by default).