I like that you can see all of your projects at once in one place, as well as view them by project manager or owner/buyer to get an overall picture for each job order from start through closeout date (and beyond).
You also have access via mobile app so there are no limits with visibility outside office hours! The only thing is it's not intuitive how things work when adding new jobs into existing orders - but we're working towards making this better now too!! We use ESP primarily out-of-office time scheduling purposes; however other clients who don't utilize our service do benefit because they receive notifications about their customers' schedule changes etc.