Dust in Veins
Very fast, I like that. Especially the clean guitars, those and the drums are what I notice most here. I can definitely hear Opeth influences, as with the shifting between growling and clean singing. I don't very much fancy bruce-dickinson style vocals though. >P
It might be my not-so-top-of-the-line system, but it seems the mixing is a little unbalanced - guitars and growling are loudest, drums and clean vocals are a little lower and bass is lowest.
HypoChrist
Sounds very In Flames apart from the drums. Fast again, that's nice. Clean vocals are more to my liking here, but still too brucey. Mixing is a lot better - only drums seem to be a bit in the background, bass is higher and clean/growls is balanced.
Razor Tears
Also very In Flames. Drums still feel a little low, but it's so little it's more a matter of taste than anything else.
All in all, I like Dust in Veins best from these early impressions, despite the mixing - or maybe because of it. It also seems the most original and varied of the three. I heard a mistake on a guitar somewhere the first time I listened to them but I can't seem to find it again so maybe I imagined it. Quite impressive for a demo!