I take Concerta (72mg a day, although some days I stick at 54mg if I don't need the top up).
It's done wonders for my executive function, as I hoped. But it's also dealt with some of the other things I didn't realise were part of ADHD (or caused by the symptoms of it, anyway). Being extremely quick to anger all the time has gone away, and my permanent exhaustion is gone - I don't know if that was from always feeling either under or over stimulated, or what, but now I'm medicated it's so much better.
It's so personal - a friend who was diagnosed as a child didn't like meds then, he wasn't old enough to understand why he felt 'different' on them and didn't like it. Now he's an adult he tried again and says they have changed his life. My nephew, who also has ADHD and is 11 years old, takes his meds on school days and likes not feeling like the odd one out in class who can't just sit and and do his work like the others, so they're great for him.
I'd say not to think of it as changing him with meds, but as giving him tools. If he needed glasses to see the whiteboard at school, you'd get them for him. He (might) need medication to enable him to learn efficiently, so give it a shot - they're not right for everyone, but if they are right for him then it will be worth it.
Plus, having experienced first-hand what untreated (not necessarily by meds, but any treatment) ADHD can do to someone's self esteem and educational experience, I'd be a strong supporter of trying to help my child however possible - it doesn't have to be meds, but they're an option, and one which can make a real difference.