I tried it a couple of times recently and didn't really like it. Smoked it through a lightbulb vapouriser I made myself, and never was able to 'break through'. I don't know if it's my method or what but it seemed like no matter how much i smoked I got hit by the proverbian ton of bricks but nothing other than that.
It's hard to describe the effect... for me, very harsh plastic tasting smoke, really bad flavour. around 10 seconds after the first hit my head would get REALLY heavy and the strangest tingling sensation would start in my head and go through my body. Usually by this point i'd be laying down, with a massive body load and racing thoughts. Every time my thoughts were 'I don't like this dont like this dont like this' and then the comedown would be most welcome, about 5 minutes or so later it would start to wear off. After about 15 minutes almost back to normal.
No visuals or 'psychadelic' effects to speak of, just massive body load, racing thoughts and overall quite uncomfortable.
I know a lot of pepole like it but it's not for me.... hope that helps