I've been doing some permutation of OCW and Ladder tests for a long time. I can generally be pretty sure it hasn't made me any more accurate, since my rifles and ammo are rarely the weak link, but at least it makes me feel like I'm cool for doing some kind of load development.
The funny part to me, disregarding the folks who argue OCW or Ladder tests shouldn't be done at all, are the arguments where guys favor one over the other. It's really doing the same thing - whether you shoot the same POA at a tall, skinny piece of paper at 300yrds or shoot a different POA's moving across a short, wide piece of paper at 100yrds, all you're doing is identifying patterns for vertical (first) and horizontal disparity, identifying a window of charge weights with the least relative disparity, then picking a weight within the window...
