Regarding the whizzer cones,I found they just didn't quite get the highs,(for my taste)...but considering their age,they did very well in their era..
I found newer speakers(especially tweeters) to have better sounding highs,(to my and Daughters ears).
When I went back and Listened to (vintage)speakers with Whizzer cones,they sounded lacking to me,found I couldn't go back to that anymore,and moved on.
In that period,I got into the HT craze,so delegated my 8 inch Whizzer cone (Radio Speakers of Canada),for affordable rear surrounds,they had good sized magnets,and conveniently mounted in wedge shaped cabs,so I secured them up in rear ceiling corners,firing down,they worked exceptionally well for this purpose for a few years.
I found HT receivers not cutting it for 2 ch playback,so,with receiver,above speakers,were sold off,and I haven't looked back,and found I I prefer 2ch,and that 2 Great speakers excel over 5 so-so ones,and cost less.That hasn't changed now for 18+ years,so doubt it ever will.
You may find whizzer highs work just fine for your personal taste,hearing,or not,all you can do is try it with the Music you enjoy,see what you think,and hey,its a Hobby,who cares what other people think/do,you only have to please yourself(& possibly significant other with looks?.
I haven't heard any of the new offerings,except MK/Alpair/Frugalhorn,so was another reasons to drop back into AK.
l read the above post too fast & I now fully understand regarding the way PG's system is set up re: using the x-over for low bass woofers.
I too like hearing tube mids/highs,especially on concerts,excellent on vocals,back up vocals,instrumentals,etc.
I've briefly tried/owned vintage and 126 Fostex full range,again,though good,didn't quite give me the highs I wanted there either.
I like tubes natural warmth,and would expect above choices of full range would be 'Very Enjoyable'!......especially with S.E.T!
...I'm thinking I may want to try that approach with my 2nd OB project..
....
Previously owned a vintage Stromberg Carson converted to 13w S.E.T,and I'll never forget while watching a No Doubt dvd,Rock Steady,through S.E.T/ Altec 19's & recall my Daughters, comment::......Wow,its like Gwen is in the room with Us!....Pretty much sums up S.E.T.,in my opinion.
Be nice if Everyone could experience S.E.T at least once in their lives!
EP concert Kenny,tonight's concert Pat Metheny Imaginary Day Live