I think you're looking for a blanket answer, but it may help you decide depending on what you consider to be better. For example:
1. Inserting Data: SSIS provides an OLE DB destination that exposes SQL Server's fastload functionality. There is no out-of-the-box component dedicated to inserting data using ADO.Net.
2. Component Support: Some components only support one connection and not the other. For example, the lookup component only supports OLE DB.
3. Metadata Change: The OLE DB Source adapter has better metadata management logic than the DataReader Source adapter.
4. Scripting: ADO.Net is preferred when used in scripts (the script task and transform only support VB.Net).
You should also look at the SSIS Connectivity White Paper. There's a link to it in the Announcements section of this forum.