The suggested method by those players will raise the average attributes fairly significantly. That said, as long as everyone is using the same system it shouldn't really affect the party member to member. You'll probably need to up your encounter strength and be prepared for more feats as the game goes on.

My group usually rolls 4db3, but on occasion I've had them roll up to 7dB3 when I specifically wanted them to be demigod like and well above the average person. It was fine.