When working with curing salts I prefer to perform the measurements in weight instead of spoons. The problem I've found in the past is that not all measuring spoons are equal.
I've seen people that use a standard small spoon that is used for eating at the table as a teaspoon for measuring, and also the same for the larger spoons and calling it a tablespoon. Other times I've seen folks that measure like my grandmother used to; if it calls for a teaspoon, better make it a heaping teaspoon!
For that reason, most ALL of my recipes have now been converted over to weight. Since we are starting with meat that is measured in weight, and not cups, it all works out well.
When measuring in grams I've also found a better consistency in my end products from batch to batch.