Two of my children have started medication recently. One has the classic "magic switch" response. There are a whole raft of things I would now never dream of attempting to do with her off her medication (homework, OT, a real conversation...) and getting her dressed and her breakfast down is the hardest part of our day, she plays for 20 mins while the medication kicks in, then miraculously self manages and does her piano practice and all her homework for the day with ease.... She was aware of the difference in herself from the first day and was very clear she felt better, liked it, wanted to keep taking medicine and wanted it to work all day every day. She did not have overt behaviour problems, particularly at school, but was simply off with the fairies to a fairly profound degree.
My other child it's much less clear if the medication works and she's not inclined to take it so we've pretty much stopped. It is possible that the things she claimed it helped with at first were genuine medication results, equally they could have been complete placebo effect. This child almost certainly has Aspergers and her ADHD symptoms may not be classic ADHD at all. I still considered her medication trial a success. We tried, nothing bad happened, we learned something... She learned to swallow tablets without having a fit. And now we've stopped.
Stimulant medications are very short acting, they work or they don't. Just don't keep at it if it doesn't work.
Both my children were still very much themselves on medication. The one for whom it clearly makes a huge difference is MORE herself on medication. She's more engaged, more creative, more productive. She's crafting, writing, producing "stuff" like never before. Her reading is dramatically improved, her handwriting, her writing, her drawing. She's easier to put to bed at night and has no trouble going to sleep. She doesn't eat much until late afternoon though. So we do make sure to give her eggs and toast in the morning and a big dinner.