To tell you the truth, I don't really know. It does give the cue a very nice, hard hit, but then again many people choose to use Elkmaster and similar soft styles of tips to dampen the hit somewhat. Old English billiards cues sometimes didn't have ferrules (maybe because a great deal of spin is used in that game?) and old snooker house cues sometimes had black fiber ferrules. Other than that, everyone I know that plays snooker has a brass ferrule on their cue.
I actually like the brass ferrule, as it is virtually indestructable. When the ferrule end of the cue gets damaged, it's usually the tenon "shoulder", the part the ferrule is resting on, not the ferrule itself. That's why really old snooker cues (40-50 years or older) are often cut short. The cue breaks before the ferrule. That is troubling, still it takes a lot of abuse for this to happen.
I actually got to try a snooker cue without a brass ferrule (some sort of pool cue material, an experiment) and IMO it felt really weak and strange. Performance wise it worked fine, but the feel was completely different and would take a lot of work getting used to. I hated the feel, but if I had started out using that, I'm sure I'd feel the same about brass. The old fiber housecues are reported to have a decent feel, but I've never tried one.