I don't think Wreath is exceptionally heavy except for the intro/outro riff. Great song anyway. I don't see Deliverance (album) as that heavy either, compared to the rest of their catalog. It is, just not enough to make it notable.
The thing I notice most is a return of all the fast doublebass parts that declined since MAYH. There there, but it just feels like Deliverance has way more. It might just be that they drums are mixed more up front. I mean, the last 5 minutes of the song BWP is practically one long fast DB roll, but I almost don't notice it.