I currently have 5 Stingray 4's.
(3) with the standard pickup and preamp
(1) with a Basslines (alnico) pickup and Basslines preamp
(1) with a Basslines (ceramic) pickup and Basslines preamp
The standard pickup and preamp are DEAD quiet - but don't have the extended top end that the Basslines pickup/preamp offer. You do get a little more "hiss" - but you also get a lot more (usable) top end. It almost sounds like a piezo pickup at times - not "brittle", but very "acoustic."
The alnico pickup is VERY bright and the ceramic pickup is a little less "acoustic" sounding - but still has more top end than the standard MM stuff.
The Basslines pickup/preamp will definitely change the overall sound of the bass. While it still has the "raw grunt" and great slapping tone - (for lack of a better word) - the Basslines guts sound more "refined." (to these ears).
I used to have a 4-94 with the Bart guts and wasn't impressed. To me, the ideal Lakland 4-94 would have the Basslines pickups and pre.
That's my 2 (okay, maybe 4) cents!