Boss Battle Gauntlet sounds like an amazing addition! I'd agree with blackice_cc in that I hope there's a reward for doing so, but even if there isn't, it sounds like such a cool challenge. (I might even brave a 3-heart Boss Gauntlet challenge, who knows!)
As for the visions, I can see how they'd be useful. But I definitely won't be using them. (Unless they have added content that is challenging, but even then, probably not.) I'm so accustomed to that game, I play it through at least twice every year, haha.