I just switched all my bows to Beman MFX Classic shafts. They are the small diameter design (like AXIS)but have a special coating over them. It brings up shaft weight a little (400's are 10.4 GPI) along with giving them strength. I picked up some brass HIT inserts from 3 Rivers, the finished arrows with 200 grain tips are at 615 grains. They penetrate like a hot knife in butter and are the toughest carbon shaft I've seen to date. Couldn't be more pleased.
I've bounced around to quite a few different heads, but none have done a better job for me than Woodsman's.