I have been using yate sip phone from untested now for several days. I think its ready for testing at least and perhaps the regular repositories. I am using it now exclusively as my sip phone and it works well. It is really great to have a reliable quality sip phone for a change. The two problem I find with yate are:
1. The ringer has to be disabled before it will accept incoming calls.
2. It hangs up (after a few seconds) an incoming call on my telephone-based home internet, but does not hang up on my cable-based office network.
I don't yet know how to make yate add a call to an existing call, so I still use Twinkle or Linphone on those occasions.
Yate has great audio and an excellent, very usable local address book. In my book, yate is superior to a cell phone when wifi is around.