I've never shot Powerbelts. I've read the many threads discussing them but have always refrained from commenting on a bullet I have no experience with.
But I can't control myself any longer and so will state my thoughts. They are based on the many pros and cons posted by those with actual experience, and my own logic.
Thought #1 - But for the price, I would not be adverse to using Powerbelts.
Thought #2 - A .50 caliber lead ball (which costs next to nothing compared to Powerbelts) will effectively kill deer with a well placed shot. So there's no reason to think a .50 caliber (non-hollow point) Powerbelt would not be just as effective. If you want to pay a buck a bullet for the loading convenience, that's fine and a personal choice.
Thought #3 - I would not use a hollow point Powerbelt.
Thought #4 - With regard to controlled expansion and penetration, a jacketed pistol bullet is very likely superior to either round balls and/or Powerbelts.
There, I've said it. I feel better now and may be able to go a few more years before feeling the need to participate in another Powerbelt thread.