Drum & Bass Amnestic ft. Bonnie Rabson - I'll Be Waiting

Just finished this one, looking for any feedback I can get!
This is the second vocal collab I have done (other is in my sig), looking for any helpful opinions I can get, as I am not used to working with vocals yet.

Also looking for any mastering tips. I find every set of speakers or headphones I listen to my stuff on has some different issue (even if they are configured properly), and can never seem to balance things properly (might sound great on one set of speakers, and then another will drown the high notes out with the sub bass, etc). Super noob at mastering and using the equalizer, so I want to improve on that.