IMO the tower, assuming it’s well designed and executed will have many advantages over a BS speaker above 80hz (and obviously below). In most cases, the BS speaker even if it has the same sized woofer, say 8”, will only have one. A competent tower will usually have two or three, and possibly more cabinet volume. That will increase its sensitivity. It will also spread the thermal load and amp power between those multiple woofers/midrange drivers. So basically you’ll have a speaker that’s easier to drive with more dynamic potential and less distortion. This is important considering how much energy is in the midrange, say even from 400hz to maybe 3000hz. A single woofer/tweeter just can’t do the same job.
Not sure why the Sansui would be a caveat. I’d think it would be an asset, although the RP8000’s should be easy to drive in any case. Unless of course you listening at very high levels. If they need a sub is dependent on a few things, mainly music choices. My mains are good to the low 30’s but for me a subwoofer(i use three) is essential.
