Man I can't even imagine vanilla Sub Zero in Tom or Denzell's hands. NRS really dropped the ball on Sub Zero's nerfs. Vanilla Sub Zero would not beat the current top 5 characters for sure.
Well, you need to understand the time frame. Subzero was not "vanilla Subzero" for very long. It was only a matter of weeks before the first patch came out. Some armor was dispensed. Subs damage was nerfed about 3% to 5% across the board. So the real day 1 Subzero didn't even exist long enough for all the Sub tech that came later to even be applied to him. And infact a lot of later Sub tech was actually in response to his nerfs. Since the things he had either didn't work or were no longer as effective, new things had to be found. But a lot of the stuff that came later you wouldn't need with vanilla sub. Those things were responses to what we lost and what we had left to work with.
An example would be the B1,2,1 standing reset. In the later version of the game this became basically a standard BnB for sub. In the earlier versions of the game it was never used because Sub hit so much harder you would be giving up to much damage to use it. And ending combos with slide had more knockdown advantage then it does now.
The 21, 21, D4, 212 parlor trick gimmicks weren't necessary with vanilla sub because 2,2 had a better hit box and clone was much better and his damage was much higher. But they took all the good stuff away, so parlor tricks is what we had left.
In fact I believe Powerup 2011 was the only tournament that had Day 1 Subzero. Heres a few.