I'm 10 almost 11 months out. I only drink the caffeinated Crystal Light at work since I work nights, 12 hour shifts. I can't remember any caffeine restrictions from my surgeon though. I think the caffeine in one pack of the Crystal Light was equal to 1/3 of a cup of coffee. Something like that.
Crystal Light is pretty much all I drink to get in my daily liquids. I think the only thing is that some of the flavors taste "sweeter" to me if that makes sense than others. I can't drink the Fruit Punch for that reason. I also have recently found that they offer different flavors with caffeine that I occasionally drink as well since I don't drink coffee or any other caffeinated drink.