Does the microphone use surface mount or through-hole components? I heard that through-hole is better. Is that true?

The Sphere microphone uses both through-hole and surface-mount. Through-hole is used on the input circuit board that connects directly to the capsule. The input circuit of condenser mics are extremely high impedance, and the capacitance and conductivity of the circuit board can become a problem. Unless special measures are taken, through-hole is generally better in this regard. The main circuit board uses surface-mount components, because the impedances of that part of the circuit are much lower.

But neither through-hole or surface-mount are inherently better than the other. Neumann and AKG use surface-mount for many, if not most, of their microphones, and achieve excellent results.