The final aggregation node does not come with the filter option.
So, no you cannot use it instead.
Beyond that, the final node in the model basically defines the general type of view.
If you want to have a flat data output with no automatic aggregation along the output columns, the projection node is used.
As soon as you work with something that resembles a cube, you'll need the aggregation.
Also, aggregation works by grouping records. That makes them unique in the output.
The projection doesn't do that.
That's very similar to the SQL behavior of queries with and without GROUP BY clause.
- Lars