RE: thunderhead 125's
I've used them since the mid 80's and was sold on them then and now. I have stuck with that broadhead all these years and don't see the need to change. Yes, they are one of the sharpest broadheads right out of the package. They can be a little tricky to tune out of high speed bows (300fps+). IMO no "standard" fixed blade flies well out of an untuned high speed bow. I am not too fond of the o-ring blade retention system but other than that I get great blood trails and pass thru's are certain with my rig when placement is right. That and I just plain love 'em!! Out of a well tuned bow I can get 3.5" groups at 60yds with them. Most will agree that they are very good broadheads and have stood the test of time!
P.S.> Be sure to use UBAR's if you shoot them with carbons, that way the o-ring won't slide down the arrow shaft and let the blades loose!