The 17-40mm L is inexpensive and weather sealed and has great build quality. The center is contrasty and reasonably sharp, even wide open at 17mm. The corners are very soft until f8 or f11. Then they're sharper but with some CA. There's a lot of fall-off. But it's an inexpensive constant aperture ultrawide. For whatever strange reason, I like the bokeh.
On APS-C I would take either the 18-55mm IS or 17-55mm IS over this lens any day. I assume I'd take the 55-85mm, too. On FF, it's good for the price but it has some distortion and it's just okay optically. Not a bad lens, but not awe inspiring.
The 70-200mm f2.8 IS II is wonderful. The 70-200mm f2.8 (non-IS) is also very good if you have a tripod or steady hands and don't mind somewhat soft corners wide open; it's a very nice lens, really.
For landscape I'd go tilt shift rather than UWA zoom (you're using a tripod, so you might as well), but the price is so high! I've got big hopes for the 24mm Rokinon TS lens.