Never hunted on the Island myself. Been there a few times on work related projects. Probably tied with Kodiak for the best trophy Sitka Blacktail hunting in Alaska. My guess is that POW has more big deer, but they are less visable due to vegetation. I gonna hunt there one of these days. Lots of book bucks come from POW. My theory is that a lot of the island (particulary the northern end) is heavy with limestone (source of calcium) and produces big racked animals.

Here's a good article about a buck taken there recently:

http://www.blacktailcountry.com/html/article3d33.htm