Pretty much the same. I have a lot of respect for Di'Anno on the early albums, and some of the early stuff Bruce does (as I noted in the live reviews on Justin's "Devil's Dancefloor") just don't sound the same when sung by him. I mean, only Di'Anno can put the psychotic terror into a song like "Killers", or even tone it back to almost ballad land on "Prodigal son". And I think he definitely does "Phantom" justice. But like people here say, had he not been replaced it's probably unlikely Maiden would have become as big as they did. It's hard to equate them with any other band, and I know Sabbath were wildly successful with Ozzy, so the comparison doesn't really stand, but when Dio joined they went in a different, more progressive direction with a lot more melody driving the songs and a shift away from (ahem) satanic styled lyrics. They almost became another band.

Dickinson brought Iron Maiden to the attention of the world, and they had their biggest hit singles and most successful albums with him. In the footage I've seen of Di'Anno live, he just doesn't seem to be feeling it, and he's almost angry with the audience, almost as if he's up there playing despite them, not because of them, as if he has something to prove. Bruce tends to embrace the audience more (not literally, as that would be gay) and draw them in, with shouts like "Scream for me [insert city here]" and so on. He's definitely a better frontman. Even having left Maiden, Di'Anno still doesn't seem to have the stage presence Bruce has.

And I bet he can't fly a 767! ;)

Is that all? He let's me call him Bruce Bruce.

Well he lets me call him Bruce. He usually calls me 'get the fuck out of my house.'

I disagree with this. I've heard hundreds of Maiden bootlegs with both men and I see it like this.

Dickinson's between song patter is rehearsed and especially catered for big arena shows and him being the showman. You hear him do several gigs and you realise nothing he says is spontaneous as he says the same thing night after night.
Not always, but quite a lot of the time.

Di Anno was more like a fan who was on stage and spoke to the audience on their own level, I guess because they were playing clubs for most of his tenure in the band. For example I remember one gig he introduced Innocent Exile (I think) by saying it's his favourite song off the Killers album. I've heard him sing this song loads of time live but can only remember hearing him saying it that one time, and that's typical of the stuff he would say between songs. I don't think I ever heard him repeat anything.

Well in fairness I've seen little of Di'Anno's live performances, so will certainly bow to your greater experience there. Actually, I've only seen Maiden the once. Oh the shame!

Could send you the full gig that the Maiden Japan E.P. was recorded from if you like.

That would be great, but I've so much on at the moment I don't know when I could say I'd get a chance to listen to it. So many Waits albums and Star Trek episodes....

Bruce

Blaze trumps 'em both.

I'm a big Maiden fan and overall Bruce is the far better vocalist. But in terms of my preferences I like Paul's work with them. He just has a gruff and an edge to his voice that Bruce doesn't. Like I said Bruce is still the far better vocalist though.