Gravity is now usable in 50 roulettes, which is a godsend for ASTs.

I think the most jarring part is less early game combat, which is rarely great, and more how much jobs change throughout the leveling process. A job you knew pre-50 can be unrecognizable at 70 or 80. Although I have no idea how that could be improved to.

I always encourage newbies to slow down, especially around the ARR-HW stopgap. Start working on a racing chocobo or farm some mounts/gear from older trials. When I was leveling I had an FC I'd check out side content with and it was a smooth process regardless of combat speed and questing.