I have used them for 3 seasons. I shoot them in the open position most of the time. It is the biggest diameter I can find for a fixed blade. 2 years ago I shot 2 of them(in the close postion) thru a brand new 55 gallon drum. One of those for hazordous waste, they are heavier than the average drum. I used my BlackKnight. Passed thru both sides of the drum. The results where the same both times lost 1 razor tip blade and 1 main blade. I thought that was a pretty good performance for a mechanical. I have used them several times in the closed position also, they have always opened for me. Just like any other mechanical, when you put it on your shaft inspect the blades and make sure they open with ease.
They really shoot well in the open position. The blade have very little sail. And they sit rite on top of the insert, this also helps. Less chance of having a flier because the head didn't spin true.
I found the will shoot thru the netting on my T2 very well. Not so with the Matrix, netting is to loose. I
f your shooting 70lbs of KE, try the 1 3/4" cut(can't shoot these in the open position). If not stick with the origanal 1 3/8ths.
I'm not going to mention any names, but a fixed blade head that I have been using for years is out of the picture. Heads won't spin and some of the blades where not even close to being sharp. So I will be shooting strictly the GrimReapers this year.
I would just like to add one more thing. Not having a rubberband to hold the blade close, you can check to make sure your blades move freely everytime you noc your arrow.