I love D4 but I wouldn't dare to play HC. I push it too hard to play defensively and will probably end up dying to dumb shit.
The game is amazing but it also dies for me as soon as I reach lvl 70-80. The gear progression just stops a couple levels into tier 4 and then there's nothing to do but grind paragon levels. Feels like tier 5 with ancient+ gear unlock is missing to make it worth it to get to lvl 100.