Difference between today and yesterday.

it is a matter of preference:

personally, i prefer the apogee duetta signature, quad 57s, infinity servostatic, koss electrostatic, accoustats, and tympany 1 d, to any speaker in current production.

Mrtennis, we seem to share this preference for planar speakers, especially for stators and I would add the Quad 63 and the good old Beveridges to your list. I've owned most of the gear you've mentioned and to this day I (at least imagine to) hear the colorations of cones, which a good planar speaker, inspite of other drawbacks simply doesn't seem to have. I've held onto my Quads 63s with Gradient subs practically until now and in the years following their first appearance never really found something better, except for stacked 57s perhaps, but now having changed house, I've finally settled for the big Sound-Labs. I've listened to a lot of (cone) speakers of current production and although I found many of them impressive in certain aspects of reproduced music, I could not agree more with your final statement. Those speakers you refer to, held the secret of "musicality", a highly subjective term of course, but sometimes, if driven right, they came uncannily close to the real thing, whereas many modern designs fail to impress me in this respect. Perhaps there are less and less concert goers amongst the designers and within the buying public. I wouldn't know.

Some say that speakers peaked in the late 60's to mid 70's and then went down hill after that.......

If we stick to sound quality...

I'd agree with the above, as the audiophile market definitely went in the directiion of art deco furniture (tall and thin - expensive veneers instead of good drivers) and "boom boom tizz" for sound (little or no midrange and sloppy mushy ported bass with etched highs). I don't blame manufacturer's as they only make what people want (sells) and makes money (low cost) and the duplicitous reviewers simply sing Hallelujah for every aesthetic new model (pretty much all get praised for their sound and the issues boil down to "flavor"...like ice cream - just pick the flavor you like)

At the low end, I think that decent sounding speakers have become very cheap compared to the past (this to me is an improvement).

In pro audio, active designs have certainly improved the sound enormously since the mid 70's. I was just in the local music store yesterday and listened to a pair of active Genelec 8050A - extremely impressive - they beat Focal, KRK, Dynaudio, Adams and Mackie's and NOT by a small margin...(by the way these were ALL active speakers, as musicians/pros rarely bother with passive anymore...of course they were also ALL ugly looking speakers - but, for some, the sound is actually relevant).

i have wondered with great interest the reviews that the older B&W matrix speakers have received, especially during the time when digital audio was still in its early stages of developement. these speakers were designed as studio monitors, and their treble response was often criticized. i also would hear them driven by earlier levinson solid state amplifiers which were a bit too "honest" in revealing poor cd-recordings as well as the sound of "jittery" cd players. later on however, i had chance to hear the 801's with pass aleph electronics and a levinson #39 cdp, with far better-recordings to boot. i could hardly recognize the "signature B&W sound"- forward and overly revealing- all that had vanished, and was replaced by a sweet/smooth musical presentation, far more like analog- not colored, but simply no longer "in your face" brashiness. in fact these were the same speakers i traded away for a pair of eggleston andras, because of the superb soft-dome tweeters they had, plus admittedly better integration of the drivers. but i also gave up some of the superb subterranean bass the 801's could produce.
so when you re-read some of the reviews during that critical period when digititis was rampant and every 6 months a slew of newer/better dacs were introduced into the market (at ever-higher prices), the "sound" of everything else also took a beating, especially speaker systems.
if i didn't hear proof of this myself i wouldn't have believed that the supposedly inferior transducers (B&W themselves trashed their crossover and tweeter for the "anniversary or series-3 model", which was not all that superior to the series-2, just a little different) weren't all that inferior- they just told you (the truth of) what was going on further up the chain of command. of course stereophile and the absolute sound never dusted off some older speaker models and listened to them again, with "better everything" feeding them a "tastier meal". now it was more in vogue to talk about speakers that cost, instead of $4-5k, speakers that delivered the goods for $8k, $12K, and $20k. and before you knew it along came speakers for over $30k, and finally 40. they were "so amazing" that the time when the B&W 802 -$4000, or the 801-$5000 (RETAIL!) were assumed to be technically challenged-designs. well go back and read what the abs.sound and stereophile had to say about them not that many years ago- that you could pinpoint musicians in an ensemble or an orchestra, that you could tell what make of bassoon a musician was playing, that you could hear a truck idling outside the recording studio, crazy stuff like that. sure, speakers have gotten better in a lot of ways, but i swallowed HARD when i upgraded to the andra's- $15,000 at the time. i just never got to hear all the things my previous speakers were capable of until after they were gone.

This always strikes me as a weird argument - that somehow older technology is supposed to be better. In nearly every area of edeavor/advancement technology is welcomed as improving results/performance. Yet somehow older audio equipment is supposed to be an exception. No way. I'd never trade the new gear with such fabulous sound for older equipment. And that's coming from someone who enjoys vintage gear; right now I have several pieces including amps and speakers which are considered past their time. They don't come close to the level of performance of the new equipment. There may be a few exceptions, extremely few. But to pursue older equipment unless on a tight budget. Never. There's an awful lot of subjective/nostalgic evaluation in the opinion that older/vintage equipment sounds as good or better than current offerings.