I wouldn't have caught that the second one was over exposed till the others mentioned it. It is, but I don't notice it as much as they do. Though I don't think it's so much over-exposure as too slow a shutter speed, at least so far as I can tell.
I also agree the composition on the first one is good, but I'd rater it better than good. I truly like it.
The first one has a slight perspective problem
I think the object in the sand is too blended in with the hill. Had you put some sand between the hill and that object, it would probably have worked better...