I have owned Swarovski and Leica high end roofs and my SE's made me sell them. There is something about the 3D effect that I get with the SE's that makes it hard to use anything else. The view of an animal through roofs looks like a flat 2 dimensional picture to me. With the SE's the animal seems to "jump" out at me, it really is a spectacular view. That said there is plenty not to like. The lack of being waterproof as others have mentioned. Bulkier and much harder to hold with elbows in and braced than a comparable roof, although it can be done. The focus wheel gets stiffer the colder it gets. And they can be a little finicky on eye placement to avoid blackouts. However for me the view through the SE's makes all these shortcomings worth dealing with.
