In most cases it compresses better than zlib.
Best of all: BICOM does not create any overhead since it is bijective (it is headerless)
Quote from the website:
If you consider compression to be an important first step before encryption, because it minimizes redundancy in the plaintext, then you can appreciate this bijective quality, because bijectivity implies that the compression adds no known plaintext to its outputBicom is open source and free to use for noncommercial purposes.
Can anyone try implement bicom in nsis? I don't have enough time to test it myself.