I guess it depends on how strict you want to get........
Example: 2TBSP serving
Skippy Natural PB
...... peanuts, sugar, palm oil & salt
carbs: 6, fiber 2 = total net carb 4
Smuckers Natural PB
......... peanuts, salt
carbs: 6, fiber 2 = total net 4
Regular Skippy PB
.....peanuts, sugar, hydrogenated vegetable oils (cottonseed, soybean/rapeseed)
carbs: 7, fiber 2 = total net carb 5
So when it comes to certain food such as PB you have to look at more then just the carb count like the ingredients in this case is more important.
IMHO Smuckers looks to be the better choice over Skippy Natural but if you're not worry about a little added sugar and prefer the taste better then Skippy Natural would be the 2nd best choice.
Sorry didn't mean to get technical but I watch my carbs also and had to start really looking at the ingredient list when it came to certain foods b/c the carb counts were either identical or extremely close. HTH and good luck!