I heard some of the CD actually in a record store and it was not mind blowin' or anything which is what I thought of his vocals live. To be honest tho, I never thought he had a strong voice in his prime in the 80's.
I think that Joey is a better singer for Anthrax than Bush...but I think that Bush is a better overall singer. If you have not heard him with Armored Saint then you are really missing out on some amazing vocal riffing. Bush can go melodic as well as strong & fierce, ala Dio.
But when he's been in Anthrax, he lowers himself to shouting out his vocals, mainly on the older Belladonna-era tracks but as well as some of the new 'Thrax material.
I'm sure that Benante and Ian don't really want 'singing' singing, if you know what I mean. They've always dogged-out anyone from the 80's who ever had a pure singing voice and I don't think that they want anything even closely resembling that in their band.