Index Match Small Rows - Trying to return w/out blanks

This is the one I usually use that removes blank cells from a list, base something on this

=IFERROR(INDEX($A$1:$A$100,SMALL(IF(($A$1:$A$100<>""),ROW($A$1:$A$100)),ROW(A1)),1),"")

red = List you are trying to reduce
blue = condition(s) for cells you want to keep (in this case those that are not blank)
green = column number you are retrieving, dependent if the original list (red) is a single column or multiple columns

You say you want to see what new data is there and what new data is not but your data comprises several fields the last of which is a value, ie a number. In many instances these numbers are different.
So is that what you're after that the numbers for a particular code have changed?
Or are you simply trying to find what codes exist/don't exist?

Why dont you just do a simple

in B6
=IFERROR(MATCH(B6,E$6,E$252,0),B6&"not in column E")
and copy down

then change the columns to check cells in column E that are not in B

If I read you correctly, you are trying to return the values that are PRSENT in BOTH lists. Use this array formula:

=IFERROR(INDEX($B:$B,SMALL(IF(ISNA(MATCH($B$6:$B$252,$E$6:$E$251,0)),"",ROW($B$6:$B$252)),ROWS($2:2))),"")

You're welcome!