the effect is similar to alcohol,but milder..

no headache, no vomiting etc...time slows down and you feel as though it can measured in millisecond.  You are very relaxed..
The "munchies" got to be a very strange feeling that you have never experienced.  You are so hungry (your stomach is empty (nothing there .. void)  you just want to eat.. anything...that is why a lot of regular users are overweight because they eat too much junk when they are high.