You are almost there...
As for now, I think you have the best library app. out there, but...
Me and my friends film collections is getting bigger for everyday. We miss the ability to make easy compares of our collections where we can sort out what the others have that I don´t have.
Today I can import collections without affecting my own library.
I can make smartcollections.
But it would be nice, perhaps with smartcollection function, to see the differens.
Make a smart "compare" collection through more than one collection at a time.
/FunkyDonut