The Audioquest (AQ) Rocket 88 with DBS system would be a noticeable upgrade, I suspect. AQ cables are a great match with Vandersteen (I have the 2CE SigIII). Vandersteen often uses AQ cables at shows, and most Vandersteen dealers sell AQ cables. You could keep your eye out for a used pair of the AQ cables that are a category better than the 88 (like the Folk Hero series), but I have been looking for just the right pair for a year! Elusive.
I STRONGLY suggest, and Richard Vandersteen does too, that you use a true biwire cable (not internally biwired single cable, which AQ does too). A pair of cables for each channel. You WILL hear the difference. A set of true biwire Rocket 88 cables will sound better than an internally biwired single cable of a higher/better series of AQ, like Folk Hero. That's what I have been told by people smarter than I including Richard V.
https://www.audioquest.com/cables