We have seen pretty drastic changes since starting medication 6 months ago.
DD is a lot more rational and logical. She doesn't procrastinate as much and there are less of the huge fights where she will spend 2 hours coming up with reasons why she should avoid a 10 minute task.
She's far less fidgety and hyper, and she can focus a lot better especially at school and even on things that don't interest her. Academically she's probably gone up 2-3 grades in every subject since starting meds and teachers have noticed a big difference.
Less emotional and far fewer meltdowns. The ones that still happen are shorter and it's easier to get through to her and talk her out of it.
She's happier - says her mind stays still and she can have one thought at a time! Sleep also improved and anxiety is no longer a thing. Friendships are less volatile and she ditched a couple of toxic friendships that I'd been unhappy about for a few years (was literally like watching the scales fall from her eyes).
Still able to hyperfocus on her interests and hasn't affected creativity or her basic personality (she is a nicer person to live with though!)
Life is much easier as we argue less, and so the dynamics have changed and even on unmedicated days it's now so much better. It feels as if her brain has rewired a bit.
I wouldn't say she's now some kind of robotic Model Child, she definitely still has plenty of normal teenage behaviours, but the difference has been pretty dramatic and with zero downsides.