just a couple of things.
just looking at that last photo and the I notice the light beams off the neons on the top of some buildings. with my photos this is just a big blur of light around them.
and second, when i done long exposures the photo is very bright. but i see yours has really nice colour with a nice dark sky still. i understand it probably comes with some editing, just was sure if you were using a filter of some kind to help with the end result.