I run a Fender P through an Ampeg head, and MB cab. It's articulate, punchy, and great in the mix (even up against a heavily scooped Mesa guitar rig).
The same bass through an Ashdown rig sounded horrid, unless I used extreme eq settings (which still sounded horrid, but at least I had some cut).
However, a Jazz; neck pup, tone rolled off, sounded really thumpy and old school through the Ashdown. Absolutely useless for Geddy-esque burp and clank with the bridge pup though.