One difference between desktop PM software and online PM software is that with desktop I could do all sorts of changes in a project plan to see potential project impacts and easily back out by not saving the file. If you need to simulate project impact based on potential future scope changes or resource changes you really can't do this online. The sandbox environment could potentially be used for this but this capability should be part of the core product. I'd like the ability to simulate scenarios within Workfront without permanently changing my project or sending out alerts.