Another benefit is that it's P2P, which doesn't do much in terms of privacy (although Bleep's website claims that it does somehow...) but it can help with censorship - think Turkey, Iran bans of apps and services. I think even Brazil wanted to ban Whatsapp at some point.

I wouldn't consider it a top 5 priority right now, but I do hope OWS takes into consideration making Signal P2P as well in the future (perhaps with some new technologies that may appear or mature by then).

My own priorities for what I want to see in Signal/Textsecure next:

1) integrated Android app

2) desktop client (ideally web/browser-based, but if that's not too secure, I could live with a native app, too, maybe one that works only through Windows 10's store for the sandbox security and digital signing benefit, as well as for the new auth features)

3) video-chat support