I have been using Prophix for financial forecasting and I have to say I like it.  It's good for having one module that has the very confidential payroll information and another that takes that information and the other costs.

What is really good is that when you want to make changes, you can create extra lines that feed into each GL code, to create a clear audit trail.  Yes you can do this with a spreadsheet but there are greater risks that if it in turn feeds other sheets that the complexity causes reconciliation issues.  Downside at present is updating from one module to the other takes many steps and about 10 mins - a pain for last minute tweaking when you know what answer you need to get to and need to be absolutely sure each step takes you there.