Time and again, I'm always slightly fascinated by the outrageous maximalist approach of these things. I don't think I'd want to own a set, even if given to me for free (although I've been tempted and did indeed bite the bullet with the SP5500X's), but I'd love to just dissect another pair of Sansui's or Kenwoods and put them against my KLH's or my Polks. Y'know, for science.
I have a pair of SP-3005, which have a 12" woofer in an appropriately sized enclosure, with three mids, and two tweeters. Should sound like a big confused mess, but it sounds a lot better than that.
I recently put out my feelers for a pair of the big woofer late 70s Sansuis, and came back with a pair of SP-X8000 speakers. Top of the line "Kabuki" in the year I was born. A friend of mine is going to bring them to me from another city, and I'll get to learn what makes them tick. The woofers are huge, and they're full of gimmicks - I'm thinking they're more like an enormous ghetto blaster than a real stereo, but that's kind of why I want to play with them.
Finally, I have a pair of SP-10 - tiny bookshelf speakers with a full range 6.5" driver. They sound quite nice for what they are.
I get the impression that there's a few eras of Sansui. I read that the company experienced a big scandal, involving labor relations, a drug deal gone bad, and the Japanese mafia, which resulted in the resignation of their founder in the mid 1970s. Products made after this point in time seem to be much cheapened and less focused on sound quality, than those made before the resignation. Apparently he wouldn't let anything out the door without listening to it first, but after he was gone, quality took a nose dive, with new management looking to maximize profit and sales instead of make high quality sound equipment. I think speakers were the earliest casualty of this shift in corporate philosophy, with amplifiers staying high quality a few years longer.
You can easily tell the shift in quality from the SP-0000 series to the SP-X0000 series, when you see the enclosures went from real wood to vinyl veneer on particle board, woofer magnets went from being very generously sized to being tiny for the size of the woofers, and crossovers went from elegant PC board designs, to a mess of glue and solder on a piece of plywood. The later speakers don't even have a low pass filter on the woofers, while the early ones have a 12dB/octave filter. I personally think both eras of product are interesting, but for sound quality alone I'd be cautious about buying anything with an X in the model number. On the other hand, the X series has the most outrageous looks, and some of the largest woofers I've ever seen in domestic hifi speakers!