One difference which is not obvious worth noting...
In PEP the default page view is set to 50% zoom, not 100% as it is in PPENG. If you are accustomed to the fine positioning of panels and buttons via your keyboards cursor keys keep in mind that at 50% zoom one key press results in a given panel or button being moved 2 coordinates, not 1. At 100% zoom or higher one key press results in a given panel or button being moved 1 coordinate. Additionally, using the right click alignment options does not always work properly at 50% zoom. A given panel or button in a grouping may still be a coordinate off from time to time. As such, I recommend always working at 100% zoom in PEP anytime you are moving panels or buttons as to ensure placement of said items is accurate. Working at 100% zoom also provides for avoiding graphic anomolies which result when working at 50% zoom. Recommended desktop for PEP by the way is at least 1600x1200 as this allows for 4 pages in the page view at a time when at 100% zoom.