Interesting, in many ways my expiernce is the opposite.
On them I do have a calmer inner mental dialog.. I dont talk to myself as much or get lost in thought. This is both good and bad.
I am restless in different ways on and off.. On I usually think alot more tomyself and have trouble quiting my mind. On them I get frustrated way more easily and therefore can be hard to stick with a task that is mentally challenging.
Off them I am more capable mentally to solve problems but less motivated physically to carry out the solution.
Its weird, on them I find it much harder to focus but more motivated to do the tasks, so i get more done usually.