PS Audio GCA or RogueM180

I realize these are two very different amplifiers. I have the PS Audio GCA 250's in my system. I have had them about 4 years. I am eyeing the Rogue Audio M180 mono blocks. Is this a sideways move or...?
Highs seem a bit harsh in my rig Any Suggestions?
Raysonic 168
PS Audio GCP200
PS Audio GCA 250 (x2 bi amp)
Von Schweikert VR-2