mmm.... not really... those pics you linked those are good pictures, probably much better than I would ever get. but are you sure the pictures would not be better with a 20mm?
I have quite a number of books on landscape photography by John Fielder, Charlie Waite, Joe Cornish, etc. Most of their photos are taken with either 20mm or 24mm. In fact I think the most used focal length is the 24mm. John Fielder said a 20-35m 50mm 80-200mm lens is ALL the lens he will EVER NEED on the field for a 35mm system. Almost everyone of the authors I have read recommends that too. Most says 24mm is enough.
I am not just reading about it. I have a 12-24mm or 18-36mm eq. on a s3pro for 1 year and taken it with me to trips to Japan and Korea. Sad to say, when you have 18mm you tend to shoot at a lot at 18mm, whether or not it is good for the composition. I do personally find my pictures better at 22mm after I switched to olympus... they are just more natural without losing the wide effect.
With a 17mm, you get the fake sense of depth which makes a picture looks initially very dramatic, but after a while it sorts of wears off on you. The kind of composition is always the same, some THING that looks unrealistically huge in the foreground. IT captures your attention cuz it isn't NATURAL. This is something I personally don't like. I feel a stunning landscape should capture nature as it is and I have seen MANY MANY good shots of nature without resorting the dramatic distortion of an ultra wide.
Just my two cents.