Like everything it depends - in this case, especially on the downstream component and how it handles SE vs. balanced input signals. Sometimes there is an extra stage for SE vs. XLR (or vice versa) that the signal has to pass through. It can be an opamp or transformer, which is definitely going to impact the sound. Best is a differential input stage, which doesn’t care whether the signal is SE or balanced.
If cost is not an object and you can avoid the pitfalls, fully balanced has advantages, but it requires doubling the circuitry and (almost) twice the expense.
For headphone amps I find balanced drive to be extremely effective, because it grants +6dB extra gain, up to 4 times the power, and double the slew rate along with common mode noise rejection. And Stax/electrostatic headphone amps have to be balanced anyways, and they sound the best (for other reasons too). For straight preamps, the advantages of balanced drive are going to be of much more subtle impact.
