Stacked/Double Advents..a modern version?

Way back...part of the birth of the "high-end", including early articles in TAS, many of us cut our audio teeth on the original large Advent used in a stacked set of 4 with the
top speaker upsidedown.

It seems that there are many companies that have flagship or near-flagship speakers with a tweeter, or two, in the center and mid/bass drivers spread up and down from the tweeters in a single cabinet or series of cabinets....kinda modern versions of double Advents. Also, most of these are very expensive speakers.

My wonderment is, has anyone tried doublets of current reasonable priced speakers? What brought this on is that my son has a pair of Kef Q15.2 in his bedroom system..and they are very good, and I started wondering...what would these be like with an other inverted pair on top?

Maybe this is old stuff, but it seems that many big-buck speakers are self-contained doublets.

Any experience/thought out there?