I like the sound they make. I've heard other players with hard tips on REVOs and it gives a certain resonance or chatter that can be used for feedback.
Be careful though, some of these tips add a lot of mass which starts to negate LD, especially on CF shafts as so little material has been removed (compared to a z2), so adding any material could be noticeable. Maybe have the tip half-lifed to start? Personally, LD is great and is a better reference, but I'm not exactly sold on its usage in American Pool so I wouldn't bother to half-life it (but it is a real concern if you're all-in on LD whatever).