I would not recommend Hal unless your 75
. Having been on both Princess and Celebrity in Alaska I would choose celebrity definitely. You will see all the same things and be offered the same tours on any line but everything on Celebrity is just a bit nicer. I get the feeling the staff cares if you are enjoying yourself and goes just that extra step. If its in budget get at least one balcony for the group, you can get nearby rooms or inside rooms across the hall and don't need one for everyone. Then you can enjoy the most scenic times such as glacier watching or sailaway from the private balcony.
Take the time and preplan your shore days. There are 100+ tour options so make sure you see all you can. Many times you can arrange a morning tour, return to the ship for lunch and then do an afternoon tour. Since everyone in your party may not want to do each tour you can spend part of the day together.