vintage versus modern speakers

Well, here is the amp I have: SAE 2401, SOLID STATE, NELSON PASS DESIGNED. Here are the specs:
Minimum Continuous RMS Power Per Channel (both channels driven 20 - 20,000 Hz at rated Distortion):
250 watts at 8 ohms
375 watts at 4 ohms
Total harmonic Distortion (from 250 mW to full rated power/at 1 watt): less than 0,025%/0,02%
Intermodulation Distortion (from 250 mW to full rated power): less than 0,025%
Clipping head Room: 0,5 dB
Damping Factor: 60

Frequency Response:
Rated Power : 20 Hz to 20 kHz +0, -0,5 dB
1 Watt [Normal/Hi-Pass]: 2 Hz - 160 kHz / 20 Hz - 160 kHz +0,25, -3 dB
Signal-to-Noise Ratio:
Rated Power (unweighted): 110 dB
Rated Power (IHF-a): 125 dB
1 Watt (IHF-A): 100 dB
Crosstalk (100 Hz to 10 kHz): greater than 70 dB
Rated Output : 2,24

Both Wolf_garcia and Ebm nailed it in their prior posts.

"Vintage" in speakers bears no correlation to wine. In this hobby it just means "old" in the context of "outdated".

Yes, I owned the JBL L100s back in their heyday and they were fine IN THEIR ERA. BUT ....

(i) The available competitors back then were comparatively few; and

(ii) that "vintage speaker " technology by today's standards is very very outdated with a matched big erosion of performance in terms of comparative performance.

(iii) Most had a big, skewed and excessively-pronounced top and bottom end to emphasize the college crown craving for "loud" and "boomy" as part of the 60s and 70s rock music offerings. That artificial "West Coast sound" (Google it) was a new manufactured sonic signature of that era designed to appeal to the college crowd masses and boomy rock discs such as Jethro Tull, The Doors, The Doobie Brothers, The Stones et al (NOTE: mostly poorly recorded offerings by today's standards = ergo the many remasters today).

"Vintage speaker" attraction today is masked in a fleeting nostalgia wrapper, because their comparative performance against today's quality product is not even close.

Actually many of these so called poorly recorded rock albums you mention of yesteryear sound much better than the poorly engineered and compressed rock and pop albums put out today. That does not mean I don't agree that most great speakers of today can sound better than the great speakers of yesterday......there are some exceptions.....and some that still sound great today........but generally one can spend less today and get much better sound per dollar than yesterday.

If you like a horn loaded speaker, and are willing to change out old cross overs, etc., vintage Klipschorns, Cornwalls and Heresy from Klipsch sound great. Many folks seek them out and prefer them to more recent offerings from other manufacturers. See Bob Crites' website. I think the same might be said for vintage JBL. There are deals to be had for one who is patient and familiarizes himself with the current market for those speakers. Good luck.

If I recall correctly, Nelson did not design any SAE stuff. I believe that Jim Bonjiorno did that basic design on your amp, although I know that Ed Miller put his hands in several amps of that era also.
Since I've chimed in... My 2 cents on the speaker discussion.
Basic design parameters hasn't changed. There were some nice speakers put out in the late 70's & 80's... Jon Dalquist had a few, Infinity, DCM was ok, recently I have been modding an Altec A7, they have turned out quite nice. What has changed is, Material technology... we now have Kevlar, carbon fiber, magnesium, aluminum, ceramic, pulp wood fiber cones & yada yada yada... This has changed along with a much improved manufacturing process. We used to have measure 50 drivers to match up a half dozen to tight tolerances. Today, they come off the line within 5% or better tolerances... Combine that with better caps & resisters along with compensation circuitry not typically used back then and normally, Yes, today, overall speakers are better, but there is no doubt that there were satisfying speakers of yesteryear that if found in good shape could offer some enjoyment.