Hi earena
I have similar questions, I know however the VO2 max workouts are helping my Crit racing however I am wondering if the Sweetspot base would be better training as this would strengthen the base , ever ongoing endeavour, doing VO2 training I have found I can go harder for longer or as Coach Chad deliver a race winning interval.
September is a big month for me and when i get to October i will swap over to building the base again (sweetspot base) but will keep doing VO2 training as i can see the reason for these painful hideous sessions!