Good reference, Pirotech. There is one statement in the comparison that merits a comment:
"These tests clearly show that zip is a clear looser. Do not use zip files unless space is not an issue - and why compress then? Well, for some reason zip is still very widely used."
This is true, and there are still good reasons for using .ZIP as opposed to .RAR or .ACE. That is, universality. Nearly everyone has a ZIP capability, and it is built in to the newer Windows OS's. And, not all files are bundled together to simply save space. Sometimes it is merely to keep them together.