I fletched up some ICS 400s with 4" right helical and slightly offset feathers about a week ago. I am also normally a 4" vane shooter and wanted to see how they perform.

As far as accuracy goes, out to 30 yards they hit right with the arrows with vanes. I have not had a problem with broadhead flight, but helical feathers should help with that 2 fold (equally fletched, feathers will normally stabalize better than vanes + you have the extra stabalization of the helical).

At 35 yards, the feather fletched arrows were hitting about 4" lower than the vane arrows. The trend continued and seperation increased as I moved farther out. I assume that had to do with the extra drag of the feathers.

Before going to feathers, you could try to put on a longer vane (5" ) and see if that helps the situation. Another option would be to put some helical on the vanes.

I don' t want this to become a which fletching type is better argument, but for hunting, I prefer vanes.

Do what you have to to get good broadhead flight, but you still have some yet to be tried options with the vanes.