I have been having a look at the new API's.  I have a problem with the ANT+PluginSampler.  no change to the code just a local build and install on an old X8.  I choose one of the displays say HR I get about a seconds worth of the plugin searching dialog then no devices are found and I then get the toast saying to check logcat for details.  I have attached the appropriate part of the log.  On my Active I have no trouble.
With the lower level Acquire channels sample I have no trouble and can get the two phones sending data between themselves.
If I get the Acquire channels sample going on the x8 and then start the ANT+PluginSampler then it works so presumably it's something to do with the initial setup of the device and reset etc.