This is a must do in our area and should be on everyone's bucket list!
Recommended flights are 1 to 2 hours. On a good day, it will allow you to explore the main divide which is both the West and East Coast sides. You will see spectacular glaciers, mountain lakes, waterfalls and wild Tahr, Chamois and deer.
As the pilot, I still get excited about these trips. The area is that spectacular.