hey, thats looking really good! honestly!
... but i guess that doesn't help you much, does it? therefore the things which would bother me:
1. why are the reflections of the chimneys so straight in the beginning? aint there water?
2. where are the reflections of the other buildings? or is it because of #3:
3. whats that brown stuff in the water (in the middle)? oil?
... if its refl. from the skyline then it doesn't match at all - #1 applies as well
4. is my monitor broken, do i need new eyes or are there all over horizontal stripes (where i would expect a smooth gradient)?
5. who is sitting on the middle chimney? ... err... nevermind...
but don't mind me armo... i'm just whining a bit. if its for background etc. i have to agree with reyrey: very nice pic!