Overall, I definitely prefer Polina to Gracie. Gracie is much more athletic and powerful while Polina is fluid and graceful. When it comes to ladies skating, I'll take fluid and graceful over athletic and powerful any day.
Gracie is more of a natural jumper which, in this sport, is always a plus. I do think Polina has to muscle her jumps from time to time but as she gets older the hope is she'll gain more strength which should increase her power overall (height in jumps, speed, etc.).
I think Polina is a lovely skater. Very Kostner-esque with her long limbs but I'm surprised by how controlled she is. Most younger skaters with those kind of limbs tend to look like Bambi; very unsteady and awkward. Polina is aware of her limbs and controls them very well. I enjoy her style of skating very much and I'm excited to see how she will progress. With a little more experience I could see her among the top ladies in the US in the coming years.