ORIGINAL: early in
Speed is a good thing, but accuracy is a better thing! If speed's that important to you then you could go lighter, but I still get pass throughs only shooting 250fps. It's really up to you.
Yep its up to you. If faster is better go for it! I shoot a 50# bow and a 620 grain arrow at about 170fps and get a pass thru and the arrow sticks in the dirt on the other side! I like heavy!