A question to the OP:
Consider the following scenario ...
Package runs at 1pm.
1) Change made to record at 1.05pm.
2) Another change made to same record at 1.10pm.
Package runs again at 1.15pm.
Your requirement is to pick up 'all changes', so I guess that means both (1) and (2), even if (2) overwrites (1) - is that correct? Otherwise, Last Modified would work OK wouldn't it?
If the answer to your question can be found with a brief Google search, please perform the search yourself, rather than expecting one of the SSC members to do it for you.