Intg Amps: Hegel 590 vs NAD M33 Masters vs Gryphon Diablo 120

Hi All: I am getting an itch to upgrade my integrated amp from Hegel 190 to something more robust that facilitates future speaker swapping.  And no, I'm not presently interested in separating components that much further (e.g. separate DAC; separate amp; clock; etc. etc).  I mainly interested in the following 3 on a used basis:

Hegel 590 OR NAD Masters 33 OR Gryphon Diablo 120

Max budget is $7500 if I choose to go towards the Gryphon (used), but curious if it's really THAT much better.   I'm particularly interested to hear from people that have had or auditioned at 2 out of 3.  The room correction on NAD is very appealing but I quite like my Hegel and it's tight control, and so something nice about staying true.

Current Setup:

* Unideal Brooklyn Apartment living room into Kitchen

* Hegel 190

* Monitor Audio Silver 7G 500

* Pine Tree Audio Cables

* Dual 1216

* Schiit Mani 2 (though I hear the phono preamp on some of above may make this superfluous)

* Spotify/Tidal (main streaming source)