Yeah at least at this stage your withdrawals will be mild or may not even happen, and sometimes you can convince yourself you're rattling when you're not (or I can at least haha). Try not to let it worry you, at worst it'll be some aches and pains, maybe some insomnia (Valium may help you here) and the shits (loperimide, the cheap £ shop shit is exactly the same as immodium, but way cheaper).
Definitely made the right decision about switching to subs. It's a real fucking hassle having to go to the clinic/pharmacy every day, being piss tested and cross examined by key workers, perhaps being "advised" to start reducing your valium too!
There's a reason they call methadone liquid handcuffs, subbies are pretty much the same thing.