Overprovisioning is only ever useful when two things are both true at the same time:
1) Your drive is full or almost full (let's say 85% full or greater -- this figure differs mainly by the drive controller and the amount of cache RAM on the drive)
2) You are thrashing the living daylights out of your drive continuously
The reason overprovisioning is helpful is that it gives the drive breathing room during times of high write activity when the background processes of the drive haven't had a chance to catch up. As long as your are treating your drive like a normal drive, and not benchmarking it (which is where all these articles are coming from), then the background garbage collection processes of the drive will quickly clean up the drive and eliminate any causes of poor performance. Think of it as the drive continuously optimising itself.
If you have overprovisioned your drive by 10%, then you have permanently given up 10% of your drive capacity for the extremely rare occasion when the above two conditions are simultaneously true.
These articles all do the same thing: fill the drive and then benchmark it. How is this relevant to real-life usage?
I think the times when overprovisioning is helpful to the average user are exactly ZERO.
