Power feeders (what speed do you run?)

I know it all depends on the cutter profile and type of wood. So lets say red oak and a 3 wing raised panel cutter. What feed rate would go if trying to do it in 1 pass, and would it change if doing a 2 pass cut.
It seems the faster I feed the better I get (less burning) but It just looks to fast for my comfort level. I have an 8 speed unit, 6.5, 13, 22, 43 ... I dont remember the rest..
I am cormfotable at the 6.5 ft/min speed, but if your going cross grain, it burns. at 22 it looks pretty good. (43 stalls the machine, more than my 3 hp shaper can handle)
What is the accepted feed rate for this type of work ?