The water is not photoshopped, but the boats are. For a long enough exposure to get the water like that, the boats would have moved. The boats are a separate exposure. On film you could do that with a very long exposure and a flash to isolate the boats.
Technically, HDR is two (or more) exposures.... One for the highlights, one for he darks.
I think it is photoshopped (see comment about the boats). The buildings are very light for the light coming form the windows, so I suspect those are also a separate exposure.
I would use slide because you can retain a great deal of detail in the shadows. The latitude of digital is roughly a dozen stops. Slide can get almost 18 if you know how to get detail in shadows. Negative can't be beat with more than 20 stops of latitude and a great ability to get detail in highlights.