Well, all of this is a matter of taste. It's more than me enjoying the quality of his voice though. I think Bruce's voice has more character, I feel that he puts more feeling and emotion into his singing. Not that JLB doesn't have any of these qualities, but I think he's a few steps below Bruce in that department. I also think Bruce's voice has more consistency. There was one period where he wasn't performing well live, but aside from that he's had very few bad nights that I've heard and his voice has aged very gracefully. JLB is a lot more hit and miss in this respect and while I'll give him leeway because of the food poisoning incident, it's still a factor. I also think Bruce hits his high notes with much more grace, accuracy, and strength than JLB. This is including JLB's performances on I&W and Awake. All these things keep JLB a step below Dickinson IMHO. But this is all taste, I can totally understand how someone would hear these things differently. Besides, saying he's a step below Dickinson really isn't all that bad considering how top tier Dickinson is.
To be fair though, I think people give Dickinson a little too much credit. Don't get me wrong, I love him, but I've heard plenty of live maiden footage where I'm anticipating some of the higher parts on songs like Hallowed Be Thy Name, and he either just sustains the previous note and basically yells the entire passage in one tone, or he throws the note away all together and just screams it out theatrically. And I don't even just mean lately. I'm talking about his performance on Live After Death, even.
And you know what? For Iron Maiden's style, it works perfectly well. And they're difficult passages, so if his voice isn't in top form, I can't blame him for throwing away some of the notes. All I'm saying is that he's not as perfect or consistent as all that.
As far as emotion and feeling goes, yeah, maybe you're right. JLB is definitely the kind of vocalist that will prioritize technique, and really try to make sure that he's hitting the proper note, rather than putting all his emotion into that note necessarily, but that's just a difference in style. I could give him just as much credit for trying to make sure that he IS hitting all the right notes. It's pretty much what I meant when I said that his style and Dickinson's style are different, and both have their strengths and weaknesses.
It also helped seeing Iron Maiden and DT live in 2010. There was a very huge difference in quality between the singers at the show I saw.
The only real difference in quality that I saw during that tour was, like I said, in stage presence and energy. In fact, during the show I went to, JLB nailed every part. Hearing that, "Watch the sparrow falling" part of pull me under, blew me away. Whereas Dickinson ended up throwing away some of the higher parts in songs like Hallowed Be Thy Name. And again, as I mentioned above, that's neither here nor there. They have different styles and prioritize different things. All I'm saying is that both have their strengths and weaknesses, and if you ask me, neither one is significantly superior over the other, it's really just a matter of taste.
Somehow it always comes down to Bruce Dickinson for some reason. Honestly, I think in terms of voice, a much more fair comparison would be Robert Plant. If you ask me, he didn't have the most soulful, or accessible voice in rock music either. Personally, I always thought he sounded quite thin. What he did have was range and technique. So in that respect, I think he and LaBrie are very similar. In fact, I knew quite a few people who actually did hear LaBrie for the first time and said, "I like it. He kinda reminds me of Robert Plant."