Soud applications Reference line stage vs line sta

I am looking for a power conditioner, and people seem to like Sound Applications Line Stage.

I just saw two postings for SA line stage. However, they are "Line Stage" and "Reference Line Stage", and they looks exactly the same from outside (except for printing). Is there any difference between them?

Yes the "Reference" versions, all 156 versions, all look the same BUT Jim Weil the designer will tell you otherwise. Every other month Jim would call and say he just changed one screw and WOW! Or he changed the paint from black to jet black and WOW! I used one and it was extremely good but gave up after several years of calls saying I just had to hear the new version!

(Dealer disclaimer)
Jim does tweak his designs a lot. His later models do outperform the earlier ones. I have two of the RLS240s (circa 2010 now superseded by the RLS-240E) and a RLS240X which he builds to order (based on the components he uses for commercial conditioners).
It's bad for resale value this way. confuses the would be buyers in the market.
The newer ones are pricier so I dont see how that is bad for resale value.
The problem is you don't know what version you are getting in the used market! Which makes even the newer pricier version not worth as much.
Thanks for all your responses.

A few local audio dealers recommended PS Audio regenerators (non of them sells PS products) given that I am living in an old apartment, so I am leaning that way for the moment.
I get mine from the local dealer so there is at least some form of providence. FWIW, very few people I know sell their Sound Applications unless it's to trade up.