This bass is important but so are these things:
Pick or fingerstyle- When I played metal I always used a pick for a little more "bite". However Steve Harris uses his fingers....
Strings: Who says you can't put flats on a bass and crank up the distortion? It sounds really dark....
F/X: I love a clean sounding bass in heavy music. But, adding a little phazer, chorus, flanger, delay and so on can be a hell of a lot of fun.
I say, choose a bass that you like clean and play with the options. For what it's worth I feel like I can dial in a nice P-Bass sound with my Jazz... I turn down my bridge pick up and dial back the tone knob a bit. I couldn't do that with my old PBass...
Good topic.
Bummer