The only plus about the Toploader 3 speed is it's bullet proof, it'll be around when the AOD is scrap metal. If you have a torquey motor like a big block, the 3 speed is fine. I used to beat small block, 4 speed cars with a 390 and a 3 speed Toploader in the 1/4. And you also have to compare the two in economics, if you already have the Toploader, and you have to rebuild the AOD to use it, how much gas does the 3 speed burn over the AOD (the difference in mileage and the cost of that extra fuel) You can buy a LOT of extra fuel with the $1500 cost of an AOD rebuild.