Speakers 10 years old or older that can compete with todays best,

In general, I have to agree. It has been my observation that in ten years any component category advances make a very sizable and worthwhile improvement to upgrade. This does not mean the old stuff is not satisfying.
 

The easiest for me to relate to is amps. I have owned and upgraded Pass amps since about 1980…every ten years. Each time I questioned if they could be worth the upgrade and each time I was so impressed I had to. I have also experienced this in speakers (owning 20 year old 10 year old and now contemporary), preamps. Of course digital really big time changes.

I used to own Apogee. They were exceptionally great sounding speakers for the money… very worthy of much higher quality inputs than many speakers. While I don’t regret getting rid of them, they were exceptional. The baby grand and grand… even more so.

@daveyf 

By the way I have a contemporary Linn LP12… nearly Klimax. I skipped the Linn phonostage and use an Audio Research Ref 3 phonostage… so avoided the digital conversion. Not sure why they did that either. 

@daveyf  “…Is it possible that more experienced a'philes will have enough knowledge/experience of how to put together a system so that it has the least chance ( i'm not saying that all of these folks will not occasionally make mistakes and regress,…”

Absolutely. I think I have upgraded probably 7 times in fifty years. The last two  times it was much easier. The most recent had a very different target sound… I nailed exactly… the analog, CD, and streamer have the same sound… exactly what I was shooting for. It was very satisfying, something that started off so difficult in the beginning, is now fun and I can accurately hit a target. 

Looking at this question, I am realizing how hard it is. In order to answer it, you must be familiar with a number of speakers brands… say five and what they sounded like ten years ago and now. More would be better. It would be really hard to compare random ten year old speakers with different speakers, since there are so many different flavors and each person has such particular tastes and listening abilities.

So ten years typically makes an important difference. Brands that I have known in the comparison include Sonus Faber, B&W, DynAudio, Kef and a couple more. Each maintained their house sound while making overall improvements.

So, the final part of the question… what does compete mean? I guess it means that in side by side test there is no competition… the newer is better, easy call. Or does it mean a notable improvement that most folks would recognize regardless of their overall liking of the house sound? So in the former case no and the later case yes.

I’m just not sure what to do with the dredged up two or three speakers that became ledgendary like Quad and never go out of favor… these are outliers. The vast majority of speaker companies that have remained in business continue to make significant improvements over time, decade by decade.