The DBD-DB2 provider is an excellent interface to DB2. The programming model is quite similar to that of native ODBC/CLI application development - with all of the friendliness and flexibility of PERL.
Programming using the provider is straightforward, yet enough sophisticated features are available to make this an ideal interface to DB2.
Internally, we use the native DBD-DB2 provider to generate on-demand, complex, multi-query reports on project status. It's performance is comparable to native applications, and meets all of our needs.