I shot some whitetails in FL with PowerBelts out of a Rem Model 700ML in .54. It killed those deer just fine, but I recovered every bullet from them. And, these were deer that didn't weigh 150 lbs. I like more penetration than that. I like 2 holes because that lets more blood out and more air in.

So, did the PowerBelts work? Yep. Would I shoot anything bigger with them? Nope. Do I still use them? Nope. To me, they are a "niche" bullet and not an all around hunting bullet. Feel free to disagree if you wish but that was my experience with them.