Back to Stages in particular:
I watched a national-level elite woman race at DLV try to setup her Stages to record a weekend of pro racing. It wanted to attach to her cell phone via BT. Cell phones (obviously) aren't allowed on the track.
She really wasn't aware of what she needed or how to configure it to record the data she wanted.
She wound up giving up and raced all weekend against other elites and had no data to show for it.