Man... Sorry to hear that about your knee, Super. Hopefully that 7 levels of hell will pay off and your knee will be good as new! The 2 reasons I went with Muzzy heads was because everyone who used them said these dudes perform well & fly true and the price of these heads were CHEAP! I bought a 6 pack of 100 grain 3-blade heads for around 25 bucks! I was paying more than that for a 3 pack of other BH brands! Can't go wrong with that!