Not necessarily. If it's twice a thick, I might cut the slices smaller. Also, remember that if you use a SF syrup instead of Splenda the ECC for slice goes down to 3, so even double that (6) is within reason.

One other thing. The Philly 1/3 less fat cream cheese (Neufchatel) is lower in carbs per serving than their regular cream cheese. Regular Philly has 1 carb per ounce, so if you use two packages (8 ounces each), that's 16 carbs added. The Neufchatel version has less than 1 carb -- probably around .5, so it's only 8 carbs for the recipe.

Nit-picking, to be sure, but there are dozens of ways to get the carb count down. Another way is to do it without a crust. Just spray the bottom of the springform pan with Pam.