Each bow has it's own "sweet spot" but I've found that to GENERALLY be around 5.8 gpp......Now, having said that, I'm shooting nearly 7 gpp at 286 fps......

If you don't have the opportunity to try out lots of different weight arrows, you have an obstacle to overcome. Because if you're like me, you don't want to buy 5 half dozen arrows to see what works best..... So, decide what your goals are....light/fast or heavy/slow and go from there. Let the spine of the arrow be the determining factor.