Well so far here's what I can say. They seem to fly about the same as the other spitfires. I sent a few into the block and they seem like they are going to do the trick. I'll report back after season starts any further feedback.
shoot any broad-head repeatedly into a block target and sooner or later something will break. most of these expandables are made for one and done on a deer. thats why they sell replacement blades and retention clips to rebuild them.
i have shot 2 deer with the 125 gr spitfire maxx and both were pass through and neither deer went more than 60 yards. great bloodtrails on both. i never recovered the arrow on the first one. the second was a 42 yard shot and the broadhead is now my "practice" tip that i shoot once in awhile for piece of mind but it always hits right with my field points. they are a good broadhead and you get 4 in a pack for the price of 3 of most other heads.
I guess I can see that with mechanical heads and the design... especially if the head is IN the foam and you have to rip it out and the blades are essentially hooked in..
I can say I've shot the same slicktrick mag and same grizztrick into foam I haven't broke or bent anything..I have a set of blade for each..I test all my ferrules and shafts with the same blades...then designate one ferrule to be my practice head and those blades stay on it..I always shoot a few broadheads every session a little before the season and through the season just to make sure all is well..
Mechanical heads have came a long way...I do carry an old rocky mountain snyper(essentially a rage before rage existed) in my quiver for a finisher or turkey killer...looking for 125gr hammerheads for the turkey killers now..a jack knife 2" cut 3 blade aughta work dandy on turkey..