This may not be news to anyone but me, but it worked for me so I'll share it just in case.
I was curious to find out what I got in my base package/upgrade from L5 to L6. Since we can't use Last Updated in the filter in the Library, I sorted by Last Updated, then used the Shift key to select everything that was updated on the day I got my upgrade. I added a My Tag to these resources (I used 'upd10-30-14').
Next, I opened Collections and created three collections. I used these collection rules to make the collections of the items that were updated in my upgrade: one for everything, one for commentaries, and one for books (remember to use whatever you tag your own resources in place of the tag I used)-
mytag:upd10-30-14
mytag:upd10-30-14 AND type:comm
mytag:upd10-30-14 AND type:monograph
Now I can sort through and find exactly what's new.