I had the 6000 dipole system with my 63s. Rather large! And quite complex what with the extra amps and the crossover. Still, it worked nicely if just a touch 'dry.' It's true that dipole bass sounds different to that from 'normal' boxes, and to my ears more natural.
Recently, I used a standard REL sub with a pair of 57s, and it sounded pretty good. However, people seem to vary a great deal in what is 'acceptable' with integrating bass. So, as always, it is a case of try it and see what you think, with your system in your room . Personally, I wouldn't be without a good sub, but a lot of my friends don't like it at all. We all seem to differ so much in what is acceptable in hi fi. Which is why these forums exist!