Magic ETL Join visual feedback (summary of join results)

one thing that i miss deeply from one of the other BI Platforms is getting some idea of what is occurring with a join.
right now, to check a join, i have to create several branches of validation to count the nulls, count the rows, check for intersections/mismatch sets, etc. all i really want is when i run preview, it would also then do some basic checks against the datasets to tell me how many rows from each table are being evaluated with the amount of mismatches from either side (join-type dependent obviously) with the total amount being returned.