I have tried and can never verify that a bow performs better at peak weight. Maybe the older ones did, but the newer ones it doesn't seem to make that big of a difference. There may be a very small difference in performance, like you may loose a few FPS, but it certainly will not be enough to notice. As far as noise, if you get a bow that makes more noise with the limbs backed off compared to one that is bottomed out, take it back! There is either something wrong or you need to get a different brand of bow.

That being said, there is nothing short of african game that a newer bow set at 60 lbs with a normal draw length (28-30 inches) will not take down. So I would opt for the 50 to 60 lb bow and bottom the limbs out. Then if you ever wanted to shoot less weight, like if you got hurt or wanted to target shoot you would have that flexibility. The only down side is I bet the bow would be easier to re-sell with a 70 lb peak weight since this is what every one wants. Too bad most of them are over bowed because they are too macho to turn the bow down a few lbs..

That is another advantage to getting the 60 lb peak weight bow. You will not be inticed to turn the bow up, which will ultimately be better for you.

Another advantage is that one of the reasons bows have adjustable weight is so you can tune the bow to the arrows. If you get arrows and they are under spined for your bow and it is a 70 lb bow turned down to 60 you can't lower the weight any to make it match your arrows. (you could cut the arrows down though if they were not too short already). If you had a 60 lb bow bottomed out you would have more range to adjust the bow down to match your arrows. This is much easier than getting new arrows or messing around having them cut and hoping it works better.

Paul