I didn't do
DCL Port adventures there, we booked private tours in each port, in fact 2 in each port.
Skagway- private plane from nearby airport to and over glacier bay, AM then a coach up white pass and train back- chilcoot charters.
Juneau- Main one- Costal copters up onto a glacier and a walk on glacier.
Booked Mount Roberts, went up twice, before and after helicopter ride.
Ketichan - private charter float plane to Misty fjords and the duck boat both direct.
Benefits
Choose my own time. Not DCL times and maybe best slots on activities booking gone.
Did my schedule.
Booked in advance got big discounts, my Misty fjords for my family only was cheaper than a DCL charter.
Personalised service.
The White pass coach whilst not booked as exclusive was in fact just us, as we went the opposite way to the typical port adventures and went in the afternoon so she was picking up, we had an almost empty rail car.