They all sound v different too, I've had a variety of each...
Fenders - USA std Jazz and P basses - passive, very organic/natural sound, fattens up nicely when rolling the tone back; just felt normal somehow...
MM - Stingray 4 & 5, active, humbucker, the most organic/natural sound I've heard from an active bass, none of that sterile/hifi sound you get from some active circuitry but could still do that slap sound, and it was [i]that [/i]slap sound you wanted to hear too; excellent QC!
G&L - L2000, L2500, L1500 - very active, something in the treble really pissed me off, sounded very dated, treble-aside they're huge sounding basses though, they also hated dead strings! Brillinatly put together though!