There are so many factors involved it's hard to say how you will be effected.

I went cold turkey off risperdal, xanax, tegretol and topomax. I stopped sleeping regular. Amix of insomina and REMless restlessness. Overall restlessness while awake. The feeling of ants crawling under my skin. And a feeling like I wanted to chew the paint off the walls. I wouldn't recommend it. Always taper. That said:

I tapered off morphine. Every adjustment was met with sleep issues and stomach issues. These lasted 2-4 days and then I was fine until the next drop.

I think sleep is effected the most with most drugs. You mess up that cocktail and sleep is the primary victim.

Ultimately you won't know until you do it. Then it's just a matter of a few days until you adjust yourself to the new mix, or was for me with morphine. So when you taper, think short term.