I lied.
I've recently found that even modafinil offers a bit of an edge to 'proceedings'. I think that with stimulants because of the increased heart rate and increased general arousal etc, you can't really tell that apart from the subjective feeling of increased excitement in the act of knocking one off.
Fortunately nowhere near as much time gets wasted on a modafinil wank compared to many other stims. Unfortunately though that substance seems to becoming less productive for me all round, even though I have increased wakefulness, that still needs to be channelled, otherwise it's easy to end up just tugging the end off it, and then being unproductive for the rest of the day just scrolling forums and social media all day by default, in the absence of making any better goals for the day and sticking to them.