I used to skate with Phantoms, and once I needed to replace my blades quite quickly (bad sharpening and I completely lost my rocker!) and they had only Phantom parabolic. I was worried about it, but quite honestly, I couldn’t really see much difference. Within five minutes it was as if I always had them. Saying that, I wouldn’t say they were better or worse than just normal Phantom blades. For me, no preference. If I needed new blades, I would buy whichever they had in the shop - Phantom or Phantom parabolic - it wouldn’t matter to me. If parabolic were more expensive, I wouldn’t want to pay the extra though because for my level of skating (single jumps), I wasn’t really feeling them being better than non-parabolic. They felt the same. But that’s my experience. Maybe there is someone who appreciates the difference.