I know Primavera pretty well. In fact, on the current project I am working on the owner requires us to use it.
Its okay for scheduling, but I think Microsoft Project is a little more user friendly. I don't use it for cost control at all. The duration of most of our projects are too short for it to have any meaningful benefits. If you ahve a 1 or 2 month job the project si finished befoire all the invoices are in.
I can see some benefit if the project is at least a year long or better.