Well, the diaphragm pickup on either original Ampeg or KK Baby Bass sounds very little like an acoustic bass - its ideal for bassy, driving salsa lines (Kris Kedzior takes out all the high mids and winds up the treble on his MarkBass combo, while having the tone rolled all the way off on his Baby Bass).
For this reason I have added a Shadow SH950 piezo pickup to my Ampeg wedged into a replacement maple bridge (I have kept the original aluminium one of course). With careful EQing it sounds pretty good as an approximation of an amplified double bass (I use the word amplified deliberately here).
KK basses are lighter and more bombproof than the original Ampeg I own (or the 'cheese bass' as my band call it), basically a more modern take. Given that they cost the same as (or only slightly more than) a Mexican factory churned-out Fender (£750-950 depending on options) I think they are excellent value for money.
For me, the Ampeg is great as I gig in London and its more portable than my 'real' DB plus I never have to worry about feedback.