they put harris at number 1. don't know why, the placement seems kind of random. one of the few metal guys to use fingers.
He certainly has dexterity and endurance. I haven't heard anything new or surprising from him on bass since the Maiden debut came out in 1980, but then the same holds true for Angus Young too. Since 1975 or so.
I always find it slightly amusing that Harris professes to "hate slap bass", yet his own style is highly percussive (and mixed that way too by the Martin Birches and Kevin Shirleys of this world), he just doesn't play funky.
For me personally, that sound would be too noisy/clattery, but of course that is exactly the ingredient that gets him heard with Iron Maiden's three lead guitar army. I think he does what he does well.