Very good article, a very good find indeed.
Unless you are abusing the heck out of your battery (high temps, leaving in sunlight, etc...) we might not actually notice the drop of the battery condition, at least I never have, but I always took care of the battery and always properly charged/discharged etc...
If you take care of the battery, you expect average to normal results, abuse it, expect to needing to buy a new battery soon me thinks.
As far as calibrating goes (using the app and wiping stats in recovery), as far as I know, this was the intention of just wiping the battery stats from memory to correct incorrect readings between battery and OS, and didn't actually provide any other benefit, correct me if I'm wrong.
Calibrating with the charger, discharging and recharging with out the phone one, and properly saturating the cells, probably provides the best case scenario for prolonging the life the battery.
But what I'm getting out of this, is if you take care of the battery, you might not notice a decrease in battery performance because of the battery condition (obviously apps and what not will drain battery so take a close look at your usage before you blame a bad battery).
Any other thoughts?