I'm doing this veg cycle and 6/18 in flower this round. I've only seen benefits in veg so far with stouter growth and more new shoots forming.
You get a plant that's easier to manage since the response from changing the light cycles won't be as drastic since the plant is not used to 18/6.
You get more controlled and manageable stretch, it's the optimal thing to do with long flowering plants with long internodes in my book. Flowering time is also shortened with longer light deprivation.
I'm curious to see what they do when I flip them in a week or two! So far it's been a good learning curve since I expected a different plant response, kinda the other way around with longer internodes and more stretch. You live and learn as long as you try new things.
Cheers!