If shooting a release (where the significant side to side movement caused by an imperfet finger release is eliminated) what downside is there to being overspined? True, its hard to paper tune accurately, but what practical detriment is there? It seems even with broadheads, there would be litle downside. I have read that even with a release there is still notable up and down flexing and thus perhaps the weaker spined arrow will absorb it and revert to true center sooner, but isn't it harder to get that stiffer arrow oscilating to begin with? Also, is the stiffer arrow going to mean better penetration becaue less energy is expended oscilating? I'm far from an expert in all the nuances of archery. However, noone has provided an explanation that clicks (may be I'm simply to thickheaded to understand). Does the equation change if a drop away rest is used and there is no arrow contact to be worked upon by some up and down oscilation? I've experienced first hand the detriment of weak spined arrows with fixed broadheads--the eratic arrow flight is quite apparent. I've simply not experienced any downside with overspined arrows. Please share your expertise, experience or wild ass speculation!