| This is a question that is not easy to answer.
Also with modern compound bows the question is not letoff, rather valley length IMHO.
Example
I shot a Hoyt UltraElite with Spirals in 2004 set to 65% letoff and shot it very well. I couldn't shoot it at 55% however because the valley was gone. The weight was not an issue, just the lack of valley.
When I changed to a Mathews Ovation I set it to 65%, however the short valley again caused me major problems. I ended up making my own draw stop and could shoot it at 72%
My next bow was a Mathews Switchback and came only in 65% and it was like shooting the UltraElite.
Finally I then moved to an Allegiance and found my best holding at 80% letoff. (BTW this was all in 4 months)
Adam is spot on that higher holding weight is better as it interferes with the string less. However just because your letoff is 12#, doesn't mean a well executed shot is made at 12#.
Just doing a quick test with some rather bad scales. My holding minimum is 12#. My actuall shooting poundage is 24-28#, ie I pull an additional 12# into the back wall which allows me to hold better in the wind.
What I like about the Allegiance set this way is that before I start pulling into the wall I can get my body settled and setup with minimal effort, at 22# this is harder to do.
__________________  |