I am currently drawing 64 lbs. I can go to 70 but want to my poundage at a very comfortable weight. I used to always set my bows at their maximum weight. With today's bows there is little need to pull 70 lbs. I also have an advantage with 31" draw length so speed is easy for me to acheive! I am actually shooting a very heavy arrow (11.3 grains per in, 30" long) with a 100 grain broadhead. Total weight of the arrow is 463 grains. I shot through a chronograph and I am right around 300 fps. I am real happy with this setup! I don't see a problem with good penetration on whitetails what so ever! This also helps keep bow noise to a minimum.
Truth of the matter is to find a weight that is comfortable to you! Being able to shoot the bow well is the #1 desired outcome. If you are comfortable at drawing 60#'s then go with it. I never noticed a difference in accuracy in my bow at 70# to 65#, only difference is in the comfort level once at full draw. If you are overly excerting yourself drawing your bow, you will not be able to hold on the target for a long period or without shaking.