I tried this recipe tonight. It turned out like liquid more then fluff, but I think I know why. You didn't rteally specify to use firm tofu. I bought soft because I thought it would be like a puree. Looking at the recipe on a different site though it states firm tofu cut into cubes. I'll try that next time.

Also for a sweetner it recomends 1/4 cup maple syrup (it's not LC obviously) I wonder though if using Atkins syrup instead of the water and splenda would work.

I've got some whipped with pumpkin atm though, it will be a nice dairy free treat since I can't handle real heavy cream without cravings.