After having listened to the 2 albums for a while, I've come to the conclusion that they're both very different from Blackwater Park, but both are equally great. Deliverance's reputation for being an album on the "hard extreme" of Opeth's range is unfounded. There were plenty of acoustic sections and plenty of clean vocals; this is not as brutal as Damnation is soft. Not nearly. But it did remind me of a typical death metal band much moreso than Blackwater Park did. The guitar work on Blackwater almost seems like it could be played by the string section of an orchestra with good results, whereas the riffage on Deliverance is more typical of what you'd expect from a metal band. The drumming on Deliverance is an improvement. Much more jazzy, not as in the background.
Damnation is truly the odd man out. This fits its reputation as Opeth's "soft extreme", but even so, it's not what I expected. None of the lighter passages of the previous two albums sound anything like this. It's brilliant.