I've had my eye on the American Fender P-Bass Deluxe for a while now, but I've never played an active bass. The on board active 3 band EQ would allow me to change styles mid song, if need be, but would that mean I could just leave the amp flat? I have a 9 band EQ on my amp, which comes in handy, but isn't exactly quick to change during a set. Secondly, does anyone here use this model and would you recommend it over the Mexican P-Bass Special (with the P/J PUs)?
What you are getting is essentially a way to boost signals. I find I still play a lot with my EQ on amp to boost my bass when I need to, but active controls on Fenders are pretty powerful. Obviously boosting the bass to full on your amp and on your bass is gonna sound a lot different then just on your amp. Your amp settings are very important too. However, it does a good job of changing the sound fairly well, and certainly a lot better then passive basses.
It depends on how much of a tone junkie you are. You may find the 3-band inadequate for shaping your tone and want to continue to use your amp.