I've been shooting the Montecs, have really like them so far. Fly like field points with the right arrow of course, but a friend and I took our boys on a pig hunt this year, my buddy made a perfect shot right behind the shoulder, I punched mine horribly right through the guts. We were both shooting the same Montecs, long story short, my pig was dead within 35 yards, he had to shoot his 2 more times, all "lethal" shots. After cutting each pig open and seeing what happened I was shocked. His arrows had found a pocket above the heart and below the lungs that was about an inch big. Had he used any expandable with the same shot it would have been devastating with one arrow instead of 3.
My shot luckily severed the main artery where the stomach and the small intestine meet.
I ended up getting my hands on a Swhacker on our bear hunt in Canada, and after seeing what it did to my buddies bear I decided to give it a try. Shot my bear at 20 yards, arrow blew through, hung up on the fletchings on the opposite side. Bear was dead within 10 seconds, I could see blood from my stand!
Check out youtube, there are a ton of videos about mechanicals versus fixed blade demonstrations. Pretty cool stuff.