The mountain light originals have goetex also. I asked the sales lady about the difference and the one thing that stood out was sizing. It mentions it on the Danner website about the wide fit vs more narrow.Not very much other than the different leather and laces. I believe the Mountain Light II are cut slightly differently.
Maybe the Mountain Light I doesn't have the goretex liner either ?
I bought mountain light ii and after wearing them for about a week around the house, I realized they were becoming softer... But also more loose. I have shorter wide feet. I normally wear 9 wide. That's what I got but after feeling too much heel lift and my feet slipping around... Went back and traded in for an 8 ee mountain light original. Man what a difference in comfort and such. I wonder if some who have had bad experience with comfort just have a slightly off size. Danner website says to go half a size smaller.
I took my time the second time around with rep and talked about how and where the boots stretches, and how to fit them properly.