Then there were 2


OK I have 3 amps on my short list but one is not available due to supply chain issues.They are ARC Ref75SE, Rogue Stereo 100, (and not available is Quicksilver Mono KT/120)
Question sin it is down to the Rogue and ARC are the comparable (or as they say a coin flip?) or is one considerably better than the other.
I like the fact that the ARC use KT150 and the bias is accessible on front panel.
jimbones
@atmasphere good point, will do. Or maybe just make it a 8 inch 2 way 8 ohm speaker.
@jimbones Well then its 8 ohms, but the efficiency in all cases remains the same. I think you're better off with the dual woofers, because you have more surface area for making bass and less excursion. Putting them in series works great for tubes.
Ref 75 SE over QS 120mono over the Rogue 
I started with Rogue  when I upgraded it was between Ref75 and Aesthetix Atlas went with Aesthetix 

Enjoy the Music 
Tom
QuickSilver V4’s over the ARC, I have first hand experience with both brands and value QS is a no brainer but also a very good sound and super reliable.  My GS150 was short lived and quality with the new ARC is questionable along with customer service.  I have friends that are dealers for both and QS is their pick to own.
Audio Research in my opinion is unquestionable the superior choice. Incredible sound, build quality over decades. Exceptional valuable over time. Also, I had recommended Rogue to a friend a long tine ago, the amp blew up during the warranty period and the owner would not repair it. I will never get over the humiliation of that recommendation.