You can do the same with with simple, in-camera, multiple exposures. It is effectively stacking, and the effects on moving subjects, or vice versa, when you move the camera, produce similar results. Though when you move the camera, the effects are more often than not, more like pointilism and you really have to work at it to produce something different. The whole idea is to experiment and produce what appeals to you and not experiment for the sake of it. At some point you have to decide what you like, what works for you and "stack" or set the number exposures that work toward that end. Looking at your two results, Mike, the second is more appealing to me. On the other hand, if it was a great expanse of water, it might work and be just as appealing. There is nothing wrong with obscuring the subject matter, or otherwise making it look different, per se, but in the end it has to appeal to you and hopefully other people. It has to express something and not just be obscure. Good results, no matter how they are done, always speak for themselves.