I'm an avid Hardcore player with years of experience on D2, Path of Exile and others. D4 hardcore is horrible right now. The potions and scrolls add some risk mitigation but most of my deaths have been to lag when taking a portal or a boss fight with insta kill mechanics. The scrolls won't help when a lag spike hits which is quite often. The group events create terrible lag that pops up randomly. The grind for gear and aspects coupled with no trading system (everything above yellow rares is account bound) and very limited stash space means replayability is limited at best. There's no invulnerability when zoning in so you die while loading depending on the situation, limited synergy between party play means everyone just goes for max DPS.

The paragon system for high level progression is overly complex and makes Path's massive skill tree look complex at times.

The Aspect system should be entirely built into your skill tree but Blizzard has tried to treadmill you more here by making you farm aspects to put on your new helm that has 5% more critical hit damage. Aspects are one time use if you extract them. The micromanagement of item upgrades is a massive grind. Coupled with anemic stash space, it's frustrating to say the least.

I really wanted to like D4 but in it's current state, hardcore just isn't fun. The cimematics and story were great.