One of the questions I get asked quite often boils down to this:
"Should I store my SSIS configuration data in SQL Server or in XML configuration files?"
And my every-so-helpful answer usually is:
That's right - very accurate, but not very useful.
Of course, for this question isn't quite as simple as it might seem at first glance, and there really is no single answer that is both generally accurate (like mine is) and useful (which mine is not) at the same time. The truly useful answer is more complex, because it relies on the context of the question more than it relies on the question itself. There is no "best" or "correct" or "right" choice for configuration storage in general - it all depends on the packages, the project and the project team.
What does this mean? I like to summarize it something like this:
- If you are using a file system deployment, it probably makes more sense to use XML configuration files.
- If you are using a SQL Server deployment, it probably makes more sense to use SQL Server configurations.
- If your ETL solution is managed by the application owner or server administrator, it probably makes more sense to use XML configuration files.
- If your ETL solution is managed by the database administrator, it probably makes more sense to use SQL Server configurations.
- If project team members and/or administrators have past experience and success with a given configuration type, it probably makes sense to use that type unless there is some compelling project-specific reason to do otherwise.
Notice that there's nothing in this list about the capabilities of the different configuration types. I've never found a problem that could be solved with one configuration type that could not also be solved with the other.
Of course, there are differences in the approaches that you use when selecting and implementing a configuration strategy for an SSIS application. And it's not always obvious how to get started, or where to go one you do get started. Fortunately, there are quite a few resources available to help make the right decision for you and to implement your configuration strategy correctly the first time. In particular, there is a small set of MSDN community articles written by SSIS-focused SQL Server MVPs about SSIS configurations. Take a look at these:
- Best Practices for Integration Services Configurations by Jamie Thomson
- Defining a Configuration Approach for Integration Services Packages by John Welch
- Understanding Integration Services Package Configurations by Rafael Salas
- Reusing Connections with Data Sources and Configurations by Matthew Roche
The articles are listed in the order of "most likely valuable" so if you don't have time to read all four, you should read the top ones first.
Check it out, and good luck!
 I blame my mother for this. My childhood was filled with conversations that went like this: "Are we having chicken for dinner, or fish?" "Yes!" "Um..." ;-)
 There is an interesting story behind these articles. Shortly before SQL Server 2008 shipped, the SSIS team asked a bunch of MVPs if they would like to write SSIS articles for MSDN. There was no guidance or suggestions provided on what topics these articles should cover. But all but one of the MVPs who provided articles independently chose to write about some aspect of configurations. To me this reinforces my belief that configurations are both one of the most important and least understood features in all of SSIS.