I would argue that it does matter for the brain. The large number of variations on the large number of different types of receptors means a great amount of variation in adaptability of the neural circuits to a great number of edge cases. But it also means there's a lot of possibility for maladaptation, such as with some presentations of mental and non-mental illnesses. Neural circuits can "remember" firing patterns through some of the varying adaptations, and not all circuit memories have the same function or the same effect.

The parent comment about varying transistor combinations was not quote correct in my opinion, as these variations in receptor makeups DO change how the neuron and circuits respond to stimuli.