A few thoughts on level scaling now that the first beta is over -
Generally speaking, I do not like enemies scaling in level with you for most games. It diminishes a sense of progression. One of the inherent characteristics of an RPG, in my opinion, is the character growth, and being able to compare and chart your progress. One-shotting enemies that used to kick your ass feels good. As long as there are enough options for players at all levels to explore, then there shouldn't be a problem.
I understand why they are doing level scaling in this game due to the shared open multiplayer world, but it still feel janky. Sure, it makes it easier to party with your friends who might be different levels than you, but oftentimes you get into a situation where your lower level friend is the one carrying you in the dungeon due to the level scaling benefiting him, and that just feels weird. As it stands, when you level up, you actually get weaker (relatively) because that one skill point you spend is not going to increase your DPS as much as the mobs' health and defense. Unless you are hoarding a bunch of twink gear, but that also diminishes the sense of exploration and discovery for new characters. Basically, the level scaling seems like too much of a concession towards the casual style of gameplay without enough benefits.
That being said, all these problems will theoretically vanish once everyone reaches max level. However, the philosophy that the real game doesn't begin until end-game is stupid to me. I don't like the fundamental nature of that type of game design. It's like saying I need to watch the first 3 seasons of a TV show before it gets good.
I liked how it was in Diablo 2. Act 1, 2, 3, 4, with clear progression levels. Normal, Nightmare, and Hell, for even more levels after that. I also liked what Diablo 3 did conceptually with Inferno difficulty, where all enemies in all acts are max level, because theoretically, you should be too at that point.