In CR 1.0, the different speed and power finishers followed an according series of tactic moves (as far as I remember, certain moves were connected to certain tactic animation subtypes).
Now, in CR 2.0, there's only one single move preparing the final strike.
I love both versions, and each of them has something the other one doesn't. So, the optimal alternative would be to have them both in the game. Logically, the current, short ones would still occur if both opponents hit in the final round, and would be "replaced" by the old ones if only one hits the final round.
After all, that's exactly what happens in the other aspects of Interlock: In hit-hit rounds, we have new grab attacks and edited power and speed moves. In hit-fail rounds, we have the old, full versions of speed and power and also the old grab animations. Doing the same with final blow animations would only naturally extend CR 2.0 and add more variation.