I'd say it is better, but it still has the same main issue that the previous iteration had.
You're primarily a casting playstyle, but you're still mostly a half-caster. You have a massive versatility, and can cast more lower-level spells but at the end of the day, you get to cast a 6th level spell at the same point that a bard or cleric is getting their 9th level spells.
I think that the additional endurance might work well in a game where there are many encounters each day, but in the games where there are only likely to be a few fights, a primary caster's ability to drop a higher-level spell when they need to is going to stand them in better stead.