GetSatisfaction is a great tool for an organization looking for an easily deployed and managed system without a ton of bells and whistles. It fits the bill for solutions where a complex reporting and management system is not needed, but a user friendly, easily accessed system is necessary. The Search and Forum approach, along with the ability to add various post types, including Bug reports and Praise, make it a suitable option for smaller to mid-size organizations.
When we first started using the application we had a need for requiring users emails be available, more detailed reporting in the admin area, the ability to add notification posts that would banner at the top, and modals upon login. Unfortunately, these are customizable features you might find in larger scale products that were not available in GetSatisfaction. Thankfully, they improve constantly and addressed the email issue in an update. The other items we were able to customize with some clever scripting.
If options like the above items, or the ability to modularly control the functionality and look and feel are requirements, GetSatisfaction may not be the best solution. It's a great option, though, if you don't need all of that.