Versions --> SQL 2005 & .Net 3.5 (C#)
Although I am almost done with my ETL (parse & load) development but during the code review one of the options suggested was why don't do all the parse and load in C# instead of splitting it between SSIS & C#. What I am currently doing is parsing the files in C#, holding data in DataSets and calling the library from SSIS to parse the set of files. The dataset is then used in SSIS to upload the data to tables in SQL Server. There are quite a few other decision making things that SSIS does, but nothing that can not be achieved in C#, fairly easily.
That option sounded quite good to me, and being a .Net developer I would lean more towards C# parsing. So I was thinking is there some basic question you should ask yourself before committing to how to parse your files? Like if you are going to use C# and call the C# code from SSIS, you better use C# for the entire thing instead of splitting it into two things. And then use SSIS just to call the C# parser at specified interval.