Maybe they listened to how he sounded on the solo album
Yeah. That and the BCSL covers disc, which is so much more compelling vocally than the actual album.
I agree.
I agree as well, but remember that we're talking about two different kinds of vocals here. Covering songs is, in some sense, easier because the melodies and a conception of what listeners expect are already there. A good cover singer will find the right balance between singing the song the way people are used to hearing it and giving it some of his own personality.
With original DT material, the melodies are whatever the writers, producers, and JLB come up with in the end. I personally think that that would be more difficult, and in JLB's case and his situation with DT, is what results in somewhat emotionless presentations. Don't get me wrong; I think his voice is great and still getting better, but it's been a while since something he sang has really given me chills like the early days.