Buying used vs new speakers from a technology perspective

Revel Salon 2 came out in 08 and still being sold as far as I know. 
 

I would put my Pioneer S-1ex up against any 10k new speaker today. 

Yep, I agree with @cd318. There hasn’t been much done to speaker design recently; same as pre-amp, in my opinion. Some improvement here and there but nothing dramatic. 

I would not say older stuff is “outdated”. There are many classic speakers 20, 30 years old that would make me happy. 
 

But also true that technology marches on. Coils, resistors, and, especially, capacitors are better than ever. Drivers are somewhat of a mixed bag. The coax driver in my Thiel CS2.4 is superb and holds up well against most of today’s drivers. But there are also breakthrough products like Vandersteen carbon driver that really set a new standard. Of course, those are $$$$$.

There has been continual improvement of speaker technology over time. If I think if the stuff of ever 2000, or 1990… in dynamic speakers… there is no comparison. Typically, I would say buying 10 years old at half the price is a screaming deal. But after that, beware.

I have owned a half dozen sets of speakers in the last 40 years. But I have auditioned dozens more. While some planar speakers of old are spectacular, they excel at a few attributes, not all. Planar, have strengths an weaknesses. After ten years regularly attending the symphony I switched back to dynamic and realized why they are the mainstay of the industry. They can do everything well. And the are moves forward year after year improving.

So after ten years, the improvements obsolete the older models.