I've done my time with mushrooms, dozens of lvl 4/5 trips in the 7-10g dry range.
For the cananbis users that are looking at trying for the first time, you will finally understand what "tripping out" means... pot doesn't make you trip out... pot is like someone giving you a slap, mushrooms (and psychs in general) is getting hit by a semi-trailer, the level of intensity is worlds apart.
Oh god, some of the things you experience
Level 5
Total loss of visual connection with reality. The senses cease to function in the normal way. Total loss of ego. Merging with space, other objects, or the universe. The loss of reality becomes so severe that it defies explanation. The earlier levels are relatively easy to explain in terms of measureable changes in perception and thought patterns. This level is different in that the actual universe within which things are normally perceived, ceases to exist! Satori enlightenment (and other such labels).
It's been 2 years since my last trip, my mind just can't handle the intensity anymore.
Best to aim for a lvl 3 trip or so, keep your ego intact, they're the most fun... when you walk into your kitchen and the toaster is 5x the size of the fridge, all the walls breathing, the entire floor is a giant kaleidoscope, you can "see" the air (its more impressive then it sounds)... just all round good fun.