The whole speed thing is stupid... the faster a metal bassist is, the more respect he gets. He sounds good! Damn good! What you need to do when you're ripping out 1/32 notes at 150 BPM, is close your eyes and ask yourself "does this sound good?"
Odds are the answer is no. I think that's the problem with most metal bands I hear compare to old ones, the bassists are playing ultra fast all the time matching the guitars instead of making a strong consistant melody. It become a mix of mud and crap. Muap if you will.
What I love about Steve Harris (I'm working some of this into my playing now that I'm in a metal band) is when he was playing a fast riff, he played rhythmically diverse. He'd put odd little breaks into what would normally be a straight sixteenth snore fest. And he played ultra melodic leads making sweet harmony riffs with the guitars (example, Number of the Beast intro). I don't care if he plays with 2 fingers, 3 fingers, I don't care if he played with a pick. It's not cheating if it sounds good.
Since metal bass playing is often following the guitar, metal bassists seem to compete. Who can play with the most fingers and play the fastest.