You do realize that branding does affect your perception of things as well?
It being the most "snappy" and "responsive" of the phones in the price range may just be your brain responding positively to the most known brand in that price range. A brand recognition that LG does pay a good deal for.
I mean, it boils down to the old "Pepsi Challenge". In the blind, people will prefer Pepsi over Coca-Cola most of the time. But if people know which is which before hand, Coca-Cola is chosen more often as being "better". (Although Pepsi is sweeter than Coca-Cola on average and people respond to sugar, which is what led to "New Coke").
Same things happen with fast food. Taking the exact same food and putting it in familiar branded packaging and people respond more favorably to it. Everything from chicken nuggets to carrot sticks.
And the converse happens. People who have convinced themselves of certain things, can have their perception of an item influenced in particular ways. Say those people who abhor fast food and only buy farm-fresh, local, organic, blah because it "tastes better". You can cut up a McDonald's chicken nugget, present it pleasantly as a local organic whatever and have people compare it to another nugget you present as a McDonald's nugget and people will sit there and tell you how they can taste the difference.
So yes, you might have bought the LG because you felt it was the snappiest phone at that price, but you only felt that way because of advertising.