Yep, I'd pretty much like to go back towards AD&D 1 & 2E for hp. Hit dice up to 9th-10th level, and then 1 or 2 hit points (no Con bonus) after that. Personally, I'd also tune HD back - Wizards d4; Artificer, Bard, Rogue, Sorcerer, Warlock d6; Cleric, Monk d8; Fighter, Ranger, Paladin d10; Barbarian d12. Monster HD would go back to being around equal to CR or less. Spells might need some tweaks, as I'd certainly knock Fireball & Lightning bolt back down to 5d6 or so. Other sources of damage would have to be tuned as well, but mostly I'm to the point in my life that I want combat to be the side show that's over quickly to allow focus on the exploration and interaction more.