Not trying to convince you otherwise, but my first reaction to Senjutsu was similar to yours. Maiden by numbers, a bit boring and uninspired. And Dickinson sounds old.
But I gave it a couple more spins and it has really grown on me. Sure, some is still Maiden by numbers, but done good and some songs sound even a bit different. Don't know if will stand the test of time, but for now I really enjoy it. This thing is a grower.
And Bruce still sounds old, but not in a tired way. He doesn't go for the insanely high notes and sometimes sounds strained, but he still has a powerful voice. And he has added a sort of fragility or vulnerability (missing the right words here) that conveys a lot of emotion.
So yeah, I'm totally trying to convince you.
Give this some more spins and see if it grows.