Not gonna vote yet, but I'm rewatching some of the 1998 RAWs right now, and one of the most noticeable things about them (other than how fukking terrible some of these shows are) is how far above the entire roster Austin is at almost everything. Like, you'll have entire shows that are top to bottom garbage that you'll have positive memories of because Austin cut a 3-minute promo that blows everything on that RAW away, blows every promo in wrestling today away, yet wouldn't even register in Austin's top 100 promos.
AJ's an all-time great and is a fantastic example of how to modify your in-ring style AND improve on your out of ring skills as you get older. However, between Survivor Series 1997 and Survivor Series 1998, Austin completely carried the WWF and bought them time to develop main event level acts to stand beside him (Rock and Foley; you can count Taker's character change if you like as well) that they desperately needed, despite really not being able to wrestle for long stretches of that period.
Think about it like this: If Austin wasn't in the WWF between Survivor Series 1997 and WrestleMania 14, what the hell would the WWF have done? Michaels was lit out of his mind every week and broke his back in January, Rock was a developing (if prodigiously talented) midcarder, Taker and Kane were tied up in their ridiculous (in both a good and bad way) storyline and neither were going to save the company from ruin if it came down to that, and Foley was doing weird shyt with Terry Funk and the New Age Outlaws while slowly developing the persona we would all come to know and love (we're not even getting into Owen being the worst babyface ever or Triple H being less interesting than his silent, jacked out girlfriend). NOBODY in that promotion could have done what Austin did at that time, which wouldn't bode well at all for a hypothetical WWF that would be missing Austin.
Note that I didn't even get to Austin's in-ring work, because there's really SO much to be said for how valuable he was to the company, and even to the wrestling business as a whole, simply through his promo and character work.
fukk it, I'm voting for Austin. I've loved AJ's work for about 15 years now, but Austin might be one of the 5 most valuable wrestlers in wrestling history. Not much of a comparison there.