They would seem to be doing all the right things, such as OTR and not rolling their own protocols, but I've only been able to find a couple of opinions and nothing concrete.
The fact that they've made effort to open source it and are letting people write their own clients for it is encouraging, but not proof that it's a solid system.
I discovered Wire a few months ago and have been impressed with its feature set. While Wire states that it is using axolotl ratchet, note that it is not the same as the Signal protocol used by Signal. Apparently Wire took the axolotl ratchet (the one Signal started with) and created a custom version for its own use. Moxie stated something of this sort in a comment recently on HN. There have also been some conflicts between Wire and OpenWhisperSystems (searching the web, in addition to reading up on Wire's site, will show you different sides of this).
To avoid confusion about axolotl ratchet and its usage, OpenWhisperSystems changed the name of the protocol used to Signal protocol in March. [1]
It must be one of the cleanest Android apps I've ever seen, yet alone messenger apps. The settings are well done, it performs great and doesn't even run a service (at least the Play Store version). Think I'm going to try to bring some of the close friends/family to this.
They would seem to be doing all the right things, such as OTR and not rolling their own protocols, but I've only been able to find a couple of opinions and nothing concrete.
The fact that they've made effort to open source it and are letting people write their own clients for it is encouraging, but not proof that it's a solid system.