I don't like or dislike you. But then I don't even think about you.
The vinyl caliper wraps have no heat dissipation property's what so ever, but due to their thin vinyl makeup they do not particularly hold heat in either.
The expensive Aluminum covers, such as MGP's are reported to have some heat dissipation properties, however most people tend not to want to spend the money on covers such as MGP's. Just because it states it is made from aluminum that does not mean that the type of aluminum used is good at dissipating heat.
For me brakes are all about stopping, not pretty. Thats why I am a fan of EBC Brake Pads or Posi Quiet Brake Pads.