We're planning a 3 week trip to Alaska next summer, and one of the things we would like to do is kayak among glaciers. I've heard that the Columbia glacier in Prince William Sound is the most spectacular, but I'm wondering if the logistics of getting to Valdez is worth it. How would Glacier Bay or Kenai compare (we'll definitely spend several days on th Kenai Peninsula)? Although we have a lot of time, we're planning 4 days in Denali, and I thought we'd start in Sitka and Juneau, and I don't want to feel like we're in transit the whole trip. Maybe skip Sitka/Junea?