Boith are great broadheads. when your talkign about the 100 grain version in either styke I don't think it much matters if it's 4 or 3 blade. I have used both & most of the time I like the 3 blade better. If I was going to shoot a Muzzy 4 blade for more cutting area it would not be the 100 grain model but instead it would be the 115 or 130 grain heads. I really like that 130 grain head. I wouldn't worry about it & I would shoot what you have. As far as penetration you won't notice any difference on deer sized animals.