I haven't heard any of the classic audio speakers, except one pair at Phil's house...and he uses the Fostex drivers recommended by Classic audio. I thought they sounded decent....I mean they were clearly not full ranges, and clearly not for large orchestral movements, but for what they are (and I understand Phil listens mainly to small acoustic arrangements) they were not bad.
I suspect that if you try to test them as other speakers (meaning for rock, or pop, or complex musical arrangements) they will not be great.
I built a pair of full ranges using very good vintage drivers, in much larger boxes (around 4 cu feet) and they have good bass, but even they are not my first choice to listen to for classical or rock music. However, they are nice for intimate jazz or acoustic type music. The argument made by several single driver hobbyists is that I personally don't know if crossovers make such a great difference. My problem with 2 way designs is that often, most of the midrange and upper is handled by a $30 tweeter, so tonality and naturalness suffers. I would rather spend the bulk of the money in a good driver that is of decent size & construction, and that covers the listening spectrum all the way from upper bass to treble. I don't have a problem with supertweeters and or subwoofers, as long as they are properly matched.
Just my opinion.
thanx!
-akhilesh