The topic of how important blade balancing is has been discussed on many threads. However after 13 hrs. of use I changed blades on my Lazer and looking at the used blades I wonder how long they actually were in balance. The buildup of grass varied on each blade. It was quite thick in spots which adds weight to the blade, and the nicks that were on the blade must affect the balance of each blade. So, how long does a balanced blade stay balanced on the machine?