I'll predict you're going to get strong consensus for salmon. They work fine in all conditions. If you're still concerned, try one, then try the other. They're just brake pads, and like tires, it might just be fun to do the research yourself if you're so inclined. Happy stopping.
I run dual compounds and salmons. To be really honest, I can't tell a difference -both are excellent -but that might be due to the fact I have different levers so hence different cable pulls and feels.
One recommendation though: whichever compound you opt to go with, go with the cartridge pads and brake shoes. The difference in price over the long term will make it worth it (it means a little more outlay initially, but again, I'd say do it if you can afford it).
The all salmon pad was developed first. It has good stopping power but squealed (noise) against the rim under heavy braking when used with some kinds of brakes. The dual compound was designed to reduce squeal, but has slightly less stopping power. Not even very noticable though. In other words, what makes them stop so well is the salmon colored part.
85 Specialized Expedition, 07 Motobecane Immortal Spirit built up with Dura ace and Mavic Ksyriums, '85 Bianchi Track Bike, '90 Fisher Procaliber, '96 Landshark TwinDirt Shark Tandem, '88 Curtlo
Probably exactly the same pad. Maybe there is some difference in size because one says for BMX and the other says Mountain Bike. I would go with the mountain bike pad. If there is any compound difference, the mountain bike is closer to a touring bike in terms of weight and size.