I've just received the SRAM Quarq TyreWiz and using the Datafield from the AppStore (which I believe is SRAM ) the connection is problematic.
I haven't found the pattern yet, but it only connects sometimes and then if you exit the Activity and start again it wont connect.
It sounds familiar to the following reported on Edge's but I don't see any reports from Forerunners. And also the pattern/work-around is not the same (I haven't figured it out yet, but it is a combination of removing datafields, rebooting etc..)
I'm running Beta 3.08.
The ANT+ communication is a bit different since it is being initiated from the data field not the watch as a Sensor.