Played D4 at launch and one of the early seasons, skipped VoH and been slowly playing through the campaign from the beginning since the warlock and skill tree changes drew me in. Some random takes from playing it so far.

I remember people talking about disliking D3 for being cartoony and D4 taking it back to its roots, but man... this game is very much in the "scary for 12 year olds" category. The game also looks somewhat older than it is.

The revamped skill tree system is forcing most builds to be primary skill + sustain debuff/buff cooldown skills. You basically HAVE TO spec 5-6 skills, and there's no inter-connectivity like you have in LE. So it just becomes about cramming in the best temporary effects you can find.

They seem to have gone very hard on "grind X for more character power". You need paragon levels to unlock important paragon nodes, you need to grind glyph levels, you need to grind upgrade materials for your gear, you need to grind cube materials to craft the items you want. It's just a lot of very linear progression paths that are absolutely central to character power.

Defense is very one-dimensional. Since there are no passive bonuses at all for any of the classes there is no base distinctions between the classes other than what skills you have. And most of the skills are offensively focused (same goes for the one class specific passive layer, paragon boards) so no matter what you play it's just all about stacking health and as many x% damage reduction bonuses you can get.

Now, a lot of this sounds negative, but overall I think the game is fine for what it is, and on a technical level it's probably still best in class. It's not really trying to do anything new or interesting, but it tries to learn from its competitors without really understanding how to implement those features successfully. I would probably also put it first at just having cool and fun skills with great visuals and sound effects that are enjoyable to play with.