I agree that the first one looks just a little bit underexposed, but not by much. How long of an exposure was the second photo? I think they are both nice, I really like the second one except that the motion in the clouds seems distracting to me. With long exposures sometimes that is unavoidable, but it looks a little weird to me. I do really like the 2nd photo though, I've been wanting to try some more landscapes with converting to B+W in mind.