Items design will be crucial
In D3 My Witch Doctor is a Legendary off-hand which does this: Makes ghost Walk(speed button) last for ever Gives 100% damage to three abilities following the use of Ghost Walk I'm really impressed by the effects this single item has on your performance.. The first thing you do is toss out Ghost Walk duration rune, and you can increase your move speed. Secondly you'll notice that your "run quickly" as well as "run away from danger" button has now become your"bang" button. This means you need to activate some brain cells, and not just spam the hotkey for speed. If Diablo 4 at start will be overflowing with legendaries X ability that deals 420% damage, and costs 69% less, to be blunt, I'd think this is a sign of a incompetence and team weakness, as well as an indication to expect mediocre performance at the very least. It's as if they went to far the opposite direction when people complained about a lack or depth to the fundamental D3 system...