To me Super 16 and 2 perf 35 are two very different paint brushes. Both formats are similar in cost as you get 22 min at 2 perf 35 for a 100 ft mag and you get 11 or so minutes /400 ft mag on SS16 (Super 16mm still is cheaper, but its not a CRAZY difference).
To me the looks are very different. I adore super 16mm, and wouldn't be afraid of the grain, its lovely. That being said, its not for everything. Sure, my initial thought is to go w/ 2 perf 35 because it is a much wider format and we are talking about landscapes, but then again good cinematography isn't always about going with the most obvious choice, so I would explore both. They are both two of my favorite formats.
Also I would heavily consider the type of shoot you are on, as it is much easier to throw a 416 on your shoulder although there are some lighter weight 2 perf options too, especially w/ 400 ft mags. I had this very same decision this fall, and because of camera avail I went with ss16 and a 416 and fell back in love with 16mm. I wouldn't count it out.