Maybe you'll think I'm being harsh, but...
HDR is like B&W. It cannot turn a dull photo into a good one. Your first shot is reasonably subtle from an HDR perspective, but it's little more than a snapshot that's been heavily PP'd. There's a huge distraction foreground right, and the only engine showing any sign of life is third in shot, occluded by the other two. Also, there's a wire in shot that appears to lead to the first engine. This should have been cloned out.
In the second shot, the HDR is hugely overdone, and the horizon isn't straight.
In the third shot the HDR has brought out an horrific level of noise in the original images. Otherwise the shot is quite nice, although I think that the maker's name should really be the sharpest point on the image, not the strings.
The waterfall is OK.
The last two shots are excellent. Huge atmosphere in both of them. But since you were HDR-ing, why didn't you do some fill recovery on the first building to bring it up a bit?
Sorry if you think I'm being mean. You did ask for comments (
) I think HDR can do wonders in bringing life to an image, but the image still needs to be a good one, and it's far too easy to overdo the effect.
Also, try inserting a line break between each image. Physically spacing them makes it easier to view each one individually.