The only thing about using
Planisphaerium as a gateway is that most other things might just disappoint you due to the drop off in intensity and brutality. Wormed is THAT good...but it's not EXACTLY pure slam in the Texas or New York style...they definitely do their own little thing here and there. Try
Butcher The Weak. If you enjoy it, find the element(s) of it you enjoy best and report back here...Nick and I should be able to find you some fairly good follow-ups soon.
Check out the blog too.
http://slam-minded.blogspot.com/