Big, oppressive vibes from the bass and kick drum on the first track! I like the way the track builds, and the harmonies do a lot to keep things interesting.
My biggest recommendation for improving the mix of the synth stuff is to keep an eye out for high-end noise — it can easily build up when you have multiple buzzy, hissy synths (or even basses!) playing at the same time. EQing the highs out of your basses would help a lot to tame the highs and keep things from getting too scratchy. :)