I have used both the XA-30.5 and XA-60.5 on my 93dB/8 ohm speakers, and there is not an appreciable difference in sound between the two amps in my system. The XA-60.5 just play louder.
If the XA-30.5 aren't creating the sound you're after, I don't think switching to the XA-60.5 is going to result in a worthwhile change.
If the XA-30.5 aren't creating the sound you're after, I don't think switching to the XA-60.5 is going to result in a worthwhile change.

