I 5 or CH 99

We are planning on travelling to Sacramento from Bakersfield. Last time we used 99 and it was pretty rough. Is I5 better than 99?

Hwy. 99 has more on and off ramps for locals, so you have to be alert for slow vehicles turning off and getting on. On I-5 you can maintain a more constant average speed. Both highways are equally smooth and bumpy.