Practices that don't have case management and are looking to change billing systems should plan to implement case management and billing in a way that the two fit together. Consider ProLaw, the time, billing and accounting modules are totally integrated with case management. TimeMatters has tight integration with Timeslips and also integrates with many other billing systems. Amicus Attorney has tight integration with PC Law Jr., Timeslips and other packages. Software Technology is about to release a new version of CaseMaster that will be competitive with the other case management systems, and it will integrate tightly with STI's TABS III billing and accounting.
Some packages have great on-screen reports that come on screen in a few seconds.
Ideally it should have aging information. This is a single most important report in many firms, and can be run by client, attorney or area of law. There are different tiers of products for different firm sizes. You will have to work the system day in and day out, so it is important to be sure the program conforms to your needs. The best of all worlds is to have the attorneys go through the training along with the staff.