I made this tonight and it's pretty nice. I used the half butter/half cream cheese method, and I used 1/2 cup of Splenda plus 8 drops of Stevia. I can always taste the bitterness of heated Splenda, so...

I took a picture and posted it.

Here are the nutrition stats with my modifications. For 1/8 of the recipe: 356 calories, 33 g fat, 10 g protein, 7 g total carb - 3 g fiber = 4 net carbs.