If you are loading a lot of data then SQL Loader will probably be faster. It will DEFINITELY be faster if you use the DIRECT=Y option, but there are some limitations when you use this option (must disable triggers and have to rebuild indexes afterwards).
If you are talking about a small amount of data, just do whatever is easiest for you.
If you will be using bind variables in you VB queries, then I wouldn't worry about the difference. If that is not possible, then use SQL Loader (SQL Loader DOES use bind variables). The use of bind variables will keep Oracle from having to
reparse your insert statements every time you execute them.
By the way, DDL statements are things like CREATE TABLE, etc. Things that create, alter or drop objects. Update/Insert/Delete are DML