The dependencies for this seem more appealing than KeePass but unless my searching skills are not up to par there don't appear to be any browser autocompletion plugins.
In fact, I usually just copy the password with Ctrl-C and the username with Ctrl-B. You can configure a secure clipboard erase after n seconds.
One thing I really wish had better support is ssh-based entry-level sync of databases[1]. Keepass has a plugin for it but I don't know the status for KeepassX 2 (currently in a non-stable release state). If I could point KeepassX at an SSH remote path and have it transparently sync at the entry level it'd be almost perfect.