Hoya 55mm HD CPL or Hoya 55mm Pro1 D CPL Filter

I would like to purchase and experiment with a CPL Filter.

I have a Sony a380 and the kit lens Sam 18-55mm . I also have the Minollta 24mm f/2.8 and the Minolta 35-105mm f/3.5-4.5 all can take a 55mm CPL filter.

I have come across two Filters from Hoya. The Hoya 55mm HD High density Digital CPL and the Hoya 55mm Pro1 D CPL Digital Filter.
Which one of the two above CPL filters will be a better choice for me. Thanks