The pearlies appear to have that lighter, almost fishing-line-like quality to them. Feels very cheap compared to early G4 hair, but it does behave just fine sometimes; my Fluttershy, Coloratura, and Starlight Glimmer all looked great right out of the package, while Pretzel and Twilight Sparkle... not so much, heh. So yeah, definitely comes down to luck I think. Some batches just come out better than others it would seem.
That said, even though the manes aren't so great, I've found the tails on recent releases benefiting from the new hair type. Again, not as good as early G4, but better than nearly all of my Rainbow Power and Crystal Princess Celebration ponies, which had the frizziest tails I have ever seen on a legit MLP.