Speaking only from personal experience, it reduces akrasia rather than eliminates it.

An odd factor is an inability to engage in pure entertainment, but I wonder if this is merely a latent psychological issue specific to me that only surfaces when taking modafinil. This seems like it's a benefit, but it can be an annoyance in regards to social interaction, almost like a classic djinn wish. Since it only lasts half a day (for me) after the first week, this isn't really a problem, though.

I recommend never taking anything with caffeine in it while on modafinil, but you might not respond as strongly to it as I do.

The most easily observed benefit for me has been not falling asleep while driving, watching movies, sitting, standing idly, etc.