The first half is kind of in the Detaching From Satan vein, but the 70's psychedelic feeling isn't as present and I don't enjoy it nearly as much. The second half with Lee Dorian singing is heavier in the sense that the riffs have more of a Celtic Frost-ish chug to them, but aside from the lead guitar (which is great all the way through) it kind of lacks atmosphere.
To be fair I'm not a big Paul Chain fan though; Detaching From Satan, In the Darkness, and Life & Death are the only others I'm familiar with.