I have read the google devs opinion on this and I also have an understanding of what they are talking about, the battery in your phone is a bit of a weird one, andoid does it's best to estimate the condition of the battery charge and display it on a meter, the OS also reacts to this when it decides that your battery is flat and shuts the device down, is the battery really flat - is it really fully charged at 100% - that is the question, the OS does its best to estimate the charge state by building a profile of the battery from when it gets charged for the first time and then goes through a learning of charging cycles and discharges all the time building a profile. There is a theory that this profile gets messed up through time and starting the leaning cycle again may have benefits for some people and some devices, it could also go the other way.
so here is what happened to me
My xperia Z1 had a full battery drain and was charged when off, when I restated the phone it was at 100% but once it reached 50-55% it suddenly went down to 2% and gave me a warning that the battery was low, this went on for a while until I eventually fully charged it and deleted the batterystats.bin file then rebooted the phone, from that time I had no more issues..........until now
I updated to LP a couple of days ago and all was well until I rebooted the phone at about 80% battery, when it restarted I got an immediate warning that the battery was low and it was showing 2%, so it went from 83% to 2% over the time it takes for a reboot, now I am going to delete the stats.bin file again once fully charged but I have a feeling this is related to LP more than anything else but is hard to tell
The google people say that the process will not improve battery life which I would agree but it may just add some linearity to how the charge cycle is displayed and giving you a better more accurate idea of the true battery status. hardware changes as it gets older, a re-profile of the battery status may not be a bad thing