Wow I really like this effect. Want to share a little of how you achieved this...?
My only thoughts is that maybe the buildings should be a little lighter so that the detail is clearer - particularly on the right side. Great job though.
I started with the sunset. Added a big black border. Cut and pasted an isolated skyline which I then enlarged with the pick tool. Used the pen tool to add white lines.
I love the colors in the sky. The rest of it really doesn't do anything for me. The border is too thick and is distracting. The skyline feels like an afterthought. It doesn't fit. Maybe if it fit inside the border it would seem like it should be there. Sorry Mike, there are just too many disconnected elements for my taste.
This picture brings me neither reality nor mystery. It appears, as if pieces of cardboards are put together for a stage decoration. The City is totally disconnected from the sky, has no lights and no details. The sky has a "crack" in it.