I do careful load development prior to settling on a load as you know - I'm not the have a guess and it'll work out sort of person. I agree, there's always a point at which grouping works well, I often find two nodes to be honest, one high and one low. I often go for the lower one to save the barrel and powder. If the MV is fast enough then why push the limits? That's just me though, I know some who will try and pack as much in there as possible. I see it as a waste of powder though, the difference in results is negligable.