My vote is for WHM AutoPilot also. It was easy to install, set up, and integrate into my site. The layout is easy to understand and the main page has most of the important information right there (incomplete orders, authorize.net batches, etc).
I also think that it will be more stable with Cpanel since it was designed to integrate with only 1 control panel. Less complexity in the control panel integration code makes for better code, IMHO.