The OP is not wrong here to ask this. I would say wanting to return a phone that's 3% worse than other models without a 3% discount on the price is fair. On the other hand, I would say..who cares? It's not like you won't be getting iPhone 7 in a few months anyway. In johns YouTube video the Samsung exported video faster anyway.
even if they all had TMSC chips you would have a difference between individual chips and as a result everyones phone will be different, it's just the silicon lottery, and then with all the other components in the phone that can affect it, someone might have a better battery, someone might have a bad one, people could go crazy trying to find a perfect phone. I would think it's possible there are some bad TMSC chips out there that might perform worse then a good Samsung one.