I have a KK BabyBass and it's pretty good. Obviously easier transporting it than a DB. Very good construction and finish. I can't compare it to a stick type EUB as I haven't used one.
What I can say is a fretless electric cannot make the same sound as a KK, they just are different animals. By the same token it doesn't sound identical to an acoustic DB either, they are different again. Another big advantage of the KK is its very easy to plug and play. It doesn't feedback, ok you could spend some time trying force it to feedback but generally they don't.
Each has its own pros and cons and it's something you have to try and find the best solution to your situation.