Personally, I've found 7zip (lzma) to have better compression than zip most of the time. That's like, 90% of the time.
MMF2 AddOn Obtainer uses 7zip compression (for MMF2AO files). When I was first taking old zip distributions and 7zipping them via the MMF2AO file format, ALL of the 7zipped extensions were smaller than their zipped counterparts.
Some a lot smaller, other just a bit. But all smaller.
So yeah, 7zip is my default choice of compression, just as png is my default choice for image formats.