Well, I don't know if I can give advice but I can at least share my own experiences with those drugs, such as they are.

I can't speak as much to the methylphenidate because I haven't taken it since I was a kid, though I will say I didn't notice it changing my behavior at the time. But then I was never very self-aware in that way as a kid, and the adults around me claimed to notice it had a substantial effect on me.

As for the atomoxetine, though, I was on it for about five years as an adult, and I can say that it is a slow buildup kind of drug. I think it took maybe a couple weeks at least for me to start seeing any beneficial effects. It wasn't a constant "on" like adderal, instead it felt like my brain was finally willing to make an appropriate level of dopamine when I was doing something that needed it, which seemed like how brains are supposed to work.