The Zoll ones are notable for having the longest storage life for the pads and also use easy to change lithium batteries available from many suppliers.
That makes their overall cost much lower than other units like the Philips, and reduces the maintenance.
The Zoll also has a fairly easy to align chest pad with built in pressure sensor for monitoring compressions.
Not sure which is the best in terms of handling the vibration of travel in a work truck though.