To be honest I can't be bothered analysing the MAIDEN album like John Q. (I do actually rate Kevin Shirley VERY highly by the way, but I agree that, apart from the bass drum sound I can't quite see what he brought Maiden that Martin Birch didn't!)
However, I thought the rock scene in 2000 needed an IRON MAIDEN album like a fish needs a bike! So why do I like the Halford album? Pure personal bias I guess. Maiden would not exist if not for Priest ( and don't start me on that one!) and as someone else said, Steve Harris ran out of riffs a looong time ago. (Did a Warren, as in Demartini, as it's called!!)