Yeah it's a great mindfuck.
Smiley is amazing. Maskell is as well.
It's an utter travesty he never got the Cassidy role in Preacher - he was made for it.
A you given A Field In England a go yet?
It's a hard watch but it contains one of the greatest scenes I've ever watched in any movie; just a surreal blend of terrific acting, editing and use of music in the 2 mins or so. It still blows my mind.
Overall though, it's requires an open mind but I do recommend it. I found it really scary.