It's your ears you must satisfy.
If you are looking for more dynamics and more bass - the difference between tube (Rogue) and solid state (Hegel) will be a significant change. The Sonetto V G2 is an excellent speaker and an improvement over the Sonetto III - the sound will evolve versus change in comparison to changing the amps you describe.
I like the Rogue sound and personally would upgrade the speakers but that's my opinion (which many folks could care less about, and in this case I think you should ignore as well)