While weighing out a gram of 2c-i into several different containers, I ended up taking upwards of 80mg (a low estimation; I was licking my surfaces and gumming etc, and dosing myself as well). Don't really know why I did it, but it happened. It was the third time I'd taken 2c-i, about a year and a half ago. Anyway, at first I was scared and the nausea and body load was intense. I'm absolutely terrified of vomiting, so I spent an anxious hour writhing on my futon before running into the shower. An hour and a half in, the visuals were like nothing I'd ever seen. Typically I get more vibrant colors, and this kaleidoscopic overlay moving over everything, but this time, everything seemed to be vibrating.
Music was unreal.
After 2 hours I became more accustomed to the visuals and the body load kicked in. Literally felt like a micro-orgasm every 20 seconds, accentuated heavily by the music (Debussy) in the background.
I wasn't functional however.
Long story short, I'd say keep 2c-b and 2c-i under 100mg. If you're gonna go for a larger dose, make sure you're prepared, be ready for the nausea. Get some good fucking headphones.