Used to use 4" on an offset but since I went to Blazers and have such great success with arrow flight and broadhead flight I doubt I go back.

One thing I noticed is you can get a harder offset with 2" Blazers as you can 4" vanes, obviously on these skinner carbons or in my case ACC's the longer the vane, the less the offset.

Nothing wrong with 4" fletch tho, we've been using it for so many years with success in the past.