I take it that the pull model has the option of using PubSub; the question is...how long does it take for a data update to show up on the callback? At this time I got access tokens for a particular user, so I am definitely authorized; however, when I manually update data on their dashboard, there is no response after some 30 minutes waiting for a callback.
The push model I understand as an additional authorization from iHealthLabs to enable real-time performance. Unfortunately, it is not available in the Sandbox, so stuck with Pull/PubSub at this time.
Thanks,
Marcos
Ended up pulling down at predefined intervals and keeping track of last sync time.