is this any good?

Definitely maybe

When I was 15 I saw a double bill at the drive-in of The Shining and The Exorcist. About a week later, I saw this on the late movie. IMO, this was scarier than The Exorcist and slightly less scary than The Shining.

People who are on the SJW spectrum might not like it, because it uses actual physically deformed people as the suffering souls of hell. This aside, it is one of the very best horror films of the 1970s.