ARC Ref 5se inferior to LS28?

My system (Yggy>REF6>ARC150SE>ML-CLX and BF210)

“I will say, it is 90% of the REF6 that replaced it in my system”
+1, @docknow. 

I purchased LS28 after auditioning both at my dealer. And I didn’t think the subtle improvements I heard with Ref6 were worth twice the price. Having said that, if Ref6 was at $10K price point, I would have grabbed Ref6 in a heartbeat. 

I am very happy with my current setup of DAC9 > LS28 > VT80. 

docknow

so in your system a fully broken in LS and REF 6 are 10% different

In my experience the REF's are always better than the LS's.  I think this tactic is a gateway to get you out of your old REF, into the current LS and then ultimately to the new REF.

The tubed power supply is significant.

@hk_fan , +1. Mere marketing tactics, nothing more.
ARC seems more prone to this hyperbole, and model turnover, than other companies though.

Now that is not to say that the LS models aren't 90% of the performance of the REF models. The law of diminishing returns hits very early in audio gear, and no manufacturer is immune. I would bet that the REF 6 gives you 90% of the performance of the REF 10.

My Transfiguration Phoenix S cartridge gives 90% of the performance of the Transfiguration Proteus. The same for my Allnic H1201 phono stage, 90% performance level of the Allnic H3000. Etc., etc., etc.

In the end, most folks pay a LOT of money for that small increase in performance. How much difference they spend, depends on how much they value the dollar versus how much they value the music.

It's an individual choice that we all make.