Buying used vs new speakers from a technology perspective

Magico, Tidal, Von Schweikert, and Rockport (etc.) all utilize advanced enclosure technology. Tidal and Magico especially use very advanced speaker cone technology. Crossover components are also improved vs 20 years ago.

How they sound in comparison? I am a relative noob and don't have the experience many on this forum have, but the technology aspect is one of my draws to this hobby. 

You will definitely pay a premium for the most advanced technology, doesn't necessary mean you will like it better though.

I love the audio folks who buy lots of new speakers, and regularly. I'd have to have millions to be in that league, but buying their used stuff is great.

Yes, the original Raidho D2 by Michael Borresen is not his latest creation, and by reports they are better, but how much?  For a third of the burl list, I got a lovely used pair in 2016. I'm keeping them; I never thought I could own such a speaker.

Yes there are probably some minor new features on Borresen designs (and well publicized by Lars, of course).  Are they worth $30k add'l to have a new Borresen B02s instead of older Raidho D2s? No, probably not for me.

No. I feel that good speakers are like wine! Vintage is good. I have Tannoy Churchill’s which get better with age….timeless. 

I am with the yes and no camp, yes on my newer model Monitor Audio Platinum PL300ii design,  but no with my older 2000 Klipsch LaScala's, of which, I'd rather have these than the newer Klipsch LaScala II design. 

Yes, they can become outdated, both in the sense that they no longer perform to their original specifications, and that they can be surpassed by newer technology.  And yes, they will eventually require repair or go past that point.  14 years is probably not a problem, but if you keep them long enough, it could be.

No, in the "can't live without" sense.

Speaker makers vary wildly in their development process.  Some build the same speaker for years or even decades.  New models may share little with their predecessors, as years of advancements are incorporated.

OTOH, KEF introduced the Uni-Q concept in 1988, and are on the 13th generation.  Changing driver materials, geometry alterations, dampers, radial reinforcements, waveguides, MAT, and lots and lots of computer modelling have led to a long series of refinements.

That doesn't mean you need to get a new pair of KEFs every couple of years.  It does keep them competitive in a fast-changing world.