Yes, speaker technology has made great strides in practicality, affordability. Sound quality too, is vastly improved within the constraints of reasonable accommodation of practical considerations. But, if you can live with the equivalent of two automobiles in your listening room, the old theater systems become sonic contenders if you value a sense of scale, extraordinary dynamics at reasonable listening levels and seemingly contradictory qualities of sounding relaxed while still sounding vivid.
I particularly like some of the modern implementation of older drivers and horns in more practical packaging, like the system Salectric has on his page (I heard that system when it was being built and tuned at Deja Vu Audio). That system is not overly huge in size and sounds extremely good in even mid-sized rooms. I have a similar type of system built around modern, but old-school woofers (paper cone, pleated paper surround, alnico magnets), 1939 Western Electric 713b compression driver and a cast metal multicellular horn, and modern bullet tweeter.
I also have heard, and liked, modern gear built on old school designs. The Shindo systems are an example, as are Edgarhorns and Goto.
I also enjoy the completely different sound of many modern designs. If these other kinds of sound are more to one's liking, then of course, modern design is vastly improved.