The only thing that presents any trouble in this for me in terms of which way I feel, is the relative win margin leading into this.
I don't think anybody, no matter their eloquence, persuasiveness or vocabulary, could convince me that Stone Cold is better than The Rock. For me, The Rock took the success of Stone Cold and built upon it, being only bigger and better then his predecessor. And once that baton was begrudgingly passed, The Rock would always be a bigger and better star that point onward (mid-way '99). People will always try to detract from The Rock claiming his success was only as triumphant because of the success of Austin, and to that I have two defences:
1) Universal star
Would a star the quality of The Rock not have been a mega-star in any other era? To claim that The Rock benefited from riding the wave of a wrestling boom caused by another mega-star, makes him a victim of timing. He was and is phenomenal, and it's not OK to think that would be any different if he hadn't immediately followed Austin. If you drop The Rock in 2005 as a new star, Cena isn't the face of the company now. He could barely compete with a Hollywood-dulled out-of-prime Rock in his own prime, how would he deal with the paragon smack-talking Rock of 2000?
2) Story benefits
If you are a fan of Stone Cold, that's generally accepted as the norm, but reluctantly there's one point that you rarely have to contend with. I very much like Stone Cold, I do think he was a very much above average talent, but I can't ever get the thought out my head when comparing him and The Rock in terms of quality, that he benefited so much from story, not just good story but by being really the very first beneficiary of a type of story that is now totally overkill, but then it was the very first of it's kind. That being the overcoming of the power-abusing authority figure. And idea totally fresh then, and one that, admittedly, Stone Cold was the perfect guy for.
But I've always felt that, in the same tone, The Rock was successful despite the stories or character's he was given. Stone Cold came from a place like that, and it was seen how he could harness his frustrations into something magical in ECW, and not long before he got the opportunity to do it on a bigger stage in WWF where it was likely to succeed. Now, you couldn't predict the scale of that success, but nonetheless. The Rock, however, worked in that place that debuted him with the stupid hair and attire, that debuted him like a precursor John Cena, clean as can be face who the crowd didn't take to, at all. The people hated him but he had the belief that if they gave him the opportunity just to talk on the mic, he had the confidence in his own ability and the foresight to know he could go places. And he didn't want to wait around. It was 2 years, almost exactly, from The debut of Rocky Maiva, that The Rock was a world champion and a main event superstar. He did it all himself, he didn't need a good programme or a good story, he just needed to believe he could outperform everybody consistently, and he did.
The Rock had to be successful despite good original stories, he needed to rely on himself and not only was he successful and able to do that, but he went on to do it better than anybody. He still holds the highest rated TV segment in weekly wrestling television, not Stone Cold. That's because he could be entertaining any time, with anyone. Outside of his world, when Stone Cold had to exist in life after being the top guy against Vinny Mac, he couldn't remain at the level of The Rock. That's why Rock faced Hogan at Wrestlemania. That's Austin turned heel at WM 17, rule of a greater heel/face. If there's a turn in a given situation, the lesser of the two heels/faces is the one that turns. And that brings me over to another point.
Matches
It's unarguable that Austin has the better record against his adversary in this match. What you can discuss is the nature of those matches. Prior to the middle of '99, not only was Austin the bigger star, he was also the face in the entirety of their encounters, and Rock was used as fodder the majority of the time to fuel the Austin/McMahon story. This is true also leading into Wrestlemania, where the face is almost always supposed to win the feud at the biggest match at the biggest stage. WM 15 booking was just standard stuff. Austin ought to have won, no problems here.
WM 17 is a whole n'other deal. People revile the winning of Austin at that event, especially the manner in which he did so. Rightfully so, as it contravened some of the essential characteristics of the Austin character, from which he would never truly recover. Point being, as in the above example, the greater face wins the feud, and at that point this was The Rock. Austin winning was the wrong decision, and if you leave that match clean, The Rock wins it hands down.
WM 19 was kind of a washout, a match that didn't really NEED to happen in retrospect, although it was nice to have it happen, neither man was really at the top of their game at this point so the win, even though it technically scores for The Rock, I don't really care about. Their WM record really should have been 1-1 for either side of the tipping of the scales in Rock's favour. Finally, there's the in-tournament booking to consider:
Tournament booking
Austin undeniably had a freshness that The Rock doesn't have here. But that works two ways. In kayfabe, that makes him the underdog which is not all that bad, because that suggests he's the face, or the premier face, which puts him in good footing to win. Austin has beaten his two opponents convincingly. But that two is a double-edged sword because the Rock defeated the person who seemed destined to be in the final of this year's tournament, the man who had just ended The Undertaker's Streak and who beat The Rock when he encountered him in their only match, and who replaced him in being the youngest world champion the WWE had then had. A man who I even voted for. Despite him beating Hulk Hogan and HHH (a guy who's traded wins and losses with The Rock as well as anyone in his career) on the way to The Rock, and despite that, people still saw fit that The Rock should win that match. That transfers that sense of destiny on to The People's Champion.
When some people look at the scores 83 v. 51 and see a steamrolling for Austin, I see Daniel Bryan at Wrestlemania. Rock can't be a heel because as a heel he wasn't at his best. Similarly too, Austin was his best as a face. When they meet face v. face, Rock wins. He eclipsed Stone Cold in that regard.
I'm not voting Rock because I don't want Austin to win his 3rd tournament, I'm voting it because The Rock was better and because contextually, 83 against 51 isn't actually going to make much difference in who wins. For me, The Rock is the greatest of all time. That's why, in a nutshell, I think he should win this tournament.