Yes, it provides the most flexibility. Opens up more cash this year to make any necessary moves which may include signing a big(ish) name who gets cut in camp, signing replacements for injuries, etc. Any cap space not used this year, rolls over into next year's cap and essentially offsets the dead money.
For instance, there is 8.9 million in dead cap next year from designating Romo as a post 6/1 cut. If the Cowboys end the season with 5 million in cap space, that 5 million is rolled into next year's cap, essentially bringing Romo's dead cap hit down to 3.9 million.