Although the different brands may have different descriptions, they are pretty much all the same compounds, and give the same results. I have also seen the argument to use soy protein or non-fat dry milk (NFDM in recipes) instead of phosphates as it is a "natural compound". Ummmmm, no it's not. Sodium Phosphate in it's various forms do occur naturally in nature and can be mined. What is sold as food grade phosphates is just the refined and purified form. Soy protein and NFDM are both a product of man and chemistry and although all of the above are safe, the phosphates are more natural than Soy and NFDM will ever be.
There are other binders that are carrot based which have been used with good results by some. I know NEPAS has used the carrot binders before and gave them a good report. I have not used the carrot binders, but personally I have used the B&P 414 and AmesPhos and love them both.
The usage quantities for B&P 414 and AmesPhos are the same as were the results for me. B&P is pretty much always available and about $6 a pound (which will last a long long time for the average home sausagemaker). AmesPhos is often out of stock. My point here is I don't think it matters what brand you use, be it AmesPhos, B&P 414, Pronto, etc.... they are all food grade phosphate compounds made for the same purpose and generally used in the same ratios (pretty much the same compound).
