I generally stick with a hunting arrow in the 380 - 400 range and have had great success with accuracy and penetration. However I can honestly say I have never stuck with a 400 + arrow for a long period of time. I will be going back to the FMJ's this off season, using them for everything from indoor target, fita, 3D and everything in between . Then sticking with them through next years hunting season. It will make for a 60 + grain weight increase. I'll admit I like the extra speed as well but I would like a long term test to see how the extra weight compares to all the other set ups I have used for any length of time.
The bows I will be using will be
Hoyt Carbon Matrix 70#
Mathews Helim 70#
and possibly the new PSE DNA 60#