this might sound weird, but the string instrument doesn't sound human enough. i can tell it's not a MIDI or the PC playing cause there's vibrato in the sound, but i don't feel the emphasis human players can make with string instruments. it just sounds too robotic than it should.
you're obviously going for a trance type music piece, and it is a good job at one. i would say add in a line in there that's lower than the string instrument. it doesn't have to be another orchestra instrument. maybe get a friend to play the electric bass (a lot of people play that apparently >_<)
everything else sounds good to me
