My best experience at McNeill River was staying behind at the cook cabin while the standard permit holders went to the falls.  I was able to hike, observe bears and just enjoy the experience without being told what to do constantly.  

The experience at Brooks Camp does not, in my opinion, harm bears or otherwise damage the environment.  You can fly over to the camp for the day or for several days, come and go from the falls as you like, hike and generally enjoy the environment and the bears.  The staff provides a good orientation but are not heavy handed.

I really do feel that McNeill River Sanctuary has both benefited from individual long-term management and suffered, as the experience becomes rather idiosyncratic and rigid.