Just got a new power amp

Looking at the specs for your amp, I'd surmise you're going to have 6 dB higher gain on the balanced input. You might not need that gain, but you could also think of it as 6 dB better s/n ratio.

Using the balanced amplifier inputs also gives it a higher input impedance. That might be a friendlier load for your streamer.

If PS audio recommend balance then that’s the way to go.

Go ahead and try out a pair of XLR's and see what you think.  Used cable or Crutchfield will allow for returns so I would not hesitate to go that route