Yes the Superlights are all leather. I started my hiking career on leather boots, none ever leaked, then I moved over to fabric type waterproof boots, they all leaked so I returned again to all leather.
I have owned 3 pairs of Superlights, I like them, they suit my feet, they are hardy and they are very easy to live with. The first two pairs never leaked, the first pair I changed because of worn soles, I've never heard of an expensive pair that solves this problem? I changed the second pair because a crack developed in the leather inside my boot, above my toes, which became just too uncomfortable for me to live with. They were already over a year old before I did a 50 day hike in the Pyrenees and they finally gave up after about the 40th day. So for me this is the first time that my cheap Berghause Superlights boots have leaked. I'm still not sure why exactly, whether it was the adhesive, a GPX problem, the heat of the summer, or something else, I just dont know? All I know is, the reality was, that on the first wet day after months of hot sun and dry weather they failed me. I've equilised my previous sole wear problem by fitting half a trainer liner under my Sorbothanes. They still wear of course but not always down one side of my boots as they used to
I am happy to buy another pair of Superlights but I might or might not? I will not do anything until after the New Year, unless I see a bargain priced pair of course! If I made the decision to go back to fabric type boots I would go back to buying a pair of Keen Targee's, they were so comforable and are just made for long hikes! I still don't go along with the expensive is best notion, sorry about that.