The truth is that ticket sales are up and most sectors are seeing punters buying all the food
Increased sales does not necessarily equate to positive yield.
As for the on-board service, my experience so far (4 flights) is that cabin crews are somewhat slow with the new process. The other day it took the cabin crew almost 40 mins to reach me in row 17 of a just under 50% loaded RJ100 on a 60 minute sector! We'd just started initial descent by that time! First lesson I've learned is that if I want to be fed and/or watered within a comfortable time frame, I'll opt for a seat in the front. I imagine that the crews will improve their speed with time and experience.