On my upcoming trip to Alaska at the beginning of July, I'm trying to decide between doing a glacier cruise in Prince William Sound (out of Whittier) or Kenai Fjords (out of Seward). Either way, the tour will be part of a day-trip from Anchorage; we have a rental car. Which I'm sure both are good, which one would be better?

I'm considering using 26 Glacier Cruise for Prince William Sound or Kenai Fjords Tours for Kenai Fjords, although I'm certainly amenable to other suggestions with regard to the best operator/tour.