I have the Cambridge 840C, and it really IS a terrific player, but it is also a bit rhythmically slow, so a waltz doesn't quite have that ONE-two-three, ONE-two-three rhythm.
LOL - rhythm cannot be adjusted. A more dynamic system will allow the accents to stand out more - this can increase the sensation of swing. HOweverm it mostly boils down to the speakers - tight criticaly damped designs with internally damped drivers will swing (preserve microdynamics or musician's emphasis/accents best). Avoid drivers that ring and underdamped designs with a bass hump - they will tend to plod along rather than swing energetically. If you think about the drum set tuning/sound that swing drummers tend to use (as opposed to rock drummers) and you will get the idea - go for speakers that are that way too - tight and lean sound.