The city is well exposed and skylines almost always make for interesting shots. I like this one very much, but would consider using perspective correction in order to reduce the converging verticals (notice the taller buildings on each side lean toward the center of the frame). While I also like the movement in the sky and reflections on the water, I would be tempted to crop out a good bit of each to make the city more prominent in the frame. If you don't want to cut out both, I'd still cut out most of one. This will still give the city more "real estate" in the image and more the horizon out of the center of the image, which, imo, will provide a more pleasing composition.
I really like this skyline a lot, though. Where's it at?
The horizon cuts the picture at the 40-60 line, which makes it neither here nor there. You need to decide which is more important - the sky, or the reflections in the water. Having both in at the same time (and in such large expanse) makes both compete for viewer's attention and draw the viewer's attention away from the city lights. (assuming that is your main intent). It would also be nice to have a dominant building grab the viewer's attention first - currently you have 2 taller buildings, and both are at separate ends of the picture, again competing for the viewer's attention.
It is a good effort though, and keep on trying! That's what most important.
