After another listen, Inertia and Mirror Pool are very good - as soon as I heard phased chords, I knew there was no way I would dislike them. These are one of the most early/mid 90s tracks Sleep D have put out.
However, I do have a feeling that, even if they are very good, they are a bit static and repetitive, and would be better if they had actually developed a bit more, musically. I do not expect an Xpander-like melody to start playing all of a sudden with filters completely open, but I do also think that they need something more than a riff.