I would go with the 60# bow, max it out and forget about it. If you have the 70# option you will always be wondering about cranking it up. Some people can pull 70 with no problem. I used to, now my 70# bows are pulling 65 and 67#. If I was maxed out at 63-64# I' d be just as happy. With the speeds/power generated from todays cams a 60 is all you need to kill deer with plenty to spare.