I often give Signal another chance, but it's UI is horrible. Some messages are not delivered, some are delivered only to Signal Desktop but not to my cell phone so I'm only notified days after the message was sent...
Signal fails 1 (the desktop app is pretty bad) and 4 (too many little problems, others won't switch). I'm starting to think Slack, of all things, might be my best solution. Really, I just want ICQ with smart phone/desktop notifications, and picture/video embedding, which doesn't seem like it should be a thing I ought to have any difficulty whatsoever tracking down in 2017.