3x mono (vintage) 1x budget (more modern)

I am looking for brief opinions.  The current setup is 5-channels, LR = Proceed HPA2, C and SS = 3x Marantz MA500 (recapped ~2yrs ago).

My question is, would it be better, same or worse to replace the MA500 amplifiers with a single Emotiva BasX A3?

The speakers are: LR = B&W 606 S2; C = Def Tech Cinepro 2000; SS = Def Tech 800.

This is for a tertiary office setup, so I realize it may not be up to some folk's standards.  :)  I am just looking for some opinions about the C and SS amplification.

Thanks!