Thanks for doing all this research Rex!
After reading this series of articles I was going to go with renting the Briartek Cerberlink for my upcoming Sierra High Route in July see http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=75737&skip_to_post=662482#662482 if you'd like to join us.
I thought I should Google the Briartek and look at some reviews first and found Rex's review here in BPL http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=77088 in which he writes "Bottom line: I will not rent the Briartek Cerberlink again. I had serious problems with both the device and the iPhone app."
Rex also wrote, "I really wanted the Cerberlink to work well". Me too. Thanks for giving it a spin and letting us know. I'm posting this here so it's connected to this series of articles.