No, totally locking the front is not the same as running a front one way. A front one way combined with a totally locked rear, reduces the amount of understeer you would otherwise get from locking the front fully, but still allows for nice long controlled slides. The front one way also acts almost like a hand brake would on a 1:1 drift car as someone else here already pointed out, allowing for weight transfer to the front when entering a corner.

For my style of driving the one way allows me to pretty much steer the car exactly where I want it to go once I've initated the slide. Before I had the one way in there I would constantly have to fight understeer to get the car excatly where I want it.