Jeff Carlsen
Adventurer
I'm just worried what the introduction of these items will do to the bounded accuracy.
These items destroy bounded accuracy. They're entirely unbalanced. In fact, most of the magic items are. That's the point. It's what makes them so magical.
If I introduced a Belt of Storm Giant Strength, it would be worn by the evil warlord who threatens the world. You would have to defeat him to get it, and that at the end of a major campaign. The players would get to play with it for a little while, and then the game would be over.
If we did keep playing, I would make the party the target of every would be assassin who wants the belt. It would become a major plot point, and eventually the players would likely give it away or destroy it.
I think I would rather the belts affect saving throws, carrying capacity, ability/skill checks, and so on, but leave bonuses to attack and damage squarely in the camp of weapons.
I would never be happy with a magic item that made you stronger but didn't actually make you stronger.
Because magic items aren't part of the math, the only truly balanced option is not to have magic items. Although, you can, with a little forethought, keep things mostly balanced if that's what you're concerned about. Then, on occasion, you should introduce something campaign shattering.