How strong the lock on new Manix2XL is, I love the knife and after seeing few videos on youtube where ball bearing lock failed am sceptic about buying it.I wish old manix was still in production with the backlock.....The new manix2 is a great design , but seeing it fail after few spine whacks will probably get a Military model!Has Spyderco fixed this problem???Ill be using my knife for construction and renovation work plus edc carry so lock strength is important to me!