Nothing wrong with the highs in the XP-20 - a little more emphasis on leading edge than the ARC. I don't mean to suggest the pre-amp is bright or siblant. You already know it isn't if you own it. As typical with tubes, ARC highs have a little more airiness, and sweetness. This may be great for female vocals, less so for hard rock guitar solos. It would be best if you could listen yourself and compare.