For those testing/using Direct Push, there is a log file created
on each device that records all the information related to the sync
process between the device and your server. The file name is 'ctrllog'
and is located in the \windows\activesync folder. One useful bit of
information from this file is the current heartbeat interval your
device is using. Values are in seconds with the device starting at 480
and increasing the interval as conditions warrant it. On my device,
the heartbeat tends to hover between 780 and 1080.
This value is critical in the consumption of battery power so if your's is hovering
at 480 most of the day your battery will most likely be consumed quickly.