Me personnely I cannot remember the last time I charged at 1C I am usually at 2C or 3C and have not noticed any change in battery integrity, and charge times are much shorter. If I am in a real hurry I will not use balance charge cuts charging time by about a third, do not recommend doing it all the time, and again I have not noticed change in battery integrity. When I notice a big change in battery resistance is when I accidently run my battery packs to low repetitively.