Drums.
First, let me say that this song shows some definite potential, and there are parts that are damn awesome, but...
I'd really advise not to use more trance/club oriented samples in a DnB song. Instead you'd be better off with some old recordings and a slicer. I'd take some drumbeat I liked and slice it up, then layer punchier kick samples on top of that.
Also, I think you need to lower the lead synth and the bass in the mix a bit, as they're drowning out the drums a little bit and taking away some of the impact of the song.
Otherwise, it isn't a bad effort, and with a little mastering and some different drum samples you could have something really interesting on your hands.