In Project Server often you find a situation where Portfolio Analyzer becomes a resource hog. On top of that cube issues sometimes make it worse. The situation happens usually if you have large number of projects, assignments & resources in your system.
Without getting nice & quick reports, the significance of an EPM system could reduce significantly. Though using Portfolio Analyzer, you can create good reports, but sometimes those are not sufficient. In one of my previous article I mentioned using MS Excel to create reports. You can also use MS Access with Project Server to create some excellent reports. You can use the Link Tables features in MS Access to link to Project Server tables. Then using SQL queries coupled with forms & reports within Access, you could create excellent reports in Access.
I’ve found an article Microsoft Project Reports on the topic. It is in fact about using MS Access with MS Project rather than MS Project Server database, even then its worth trying.