Even Chris mentioned the same thing. Why they don't use him more- because he has only one sound- same as ozzy.
I like Mats in Perrenial Sophia. He sang in a lower pitch more like American singing. Even when they scream in American band its not the same scream. The 80s/East Europe metal has men with high pitched voices screaming through the whole song and it sounds cool once in a while when they hit a high note but it gets annoying after a while. Especially most Americans don't like that style anymore.
Good singing would be like scott wyland (spelling?) stone temple pilots- interstate song, or in Velvet Revolver- fall to pieces, just sixteen etc. Or like Disturbed is good. Good screams- metallica which isn't all ear piercing. The old guns n roses style singing was cool for a while but gets old when you listen to it all the time. Yet Europe is stuck on this 80s sound for some reason. I hear a lot of good bands but they are doing nothing original just repeating stuff that's already been done.
People with unique voices- dude from redhotchilipeppers. Ozzy obviously. Piotr just doesn't come anywhere near those singers. Nor do I think he's as good as Mats Leven, Lori Lewis, Snowy Shaw, Thomas Vikstrom. He's like a B level singer he sounds good but not A level- not like super star material.
New reply posted while I was typing: nah I think the opera is a significant part of the music in symphonic metal. I like opera metal.
It's a matter of taste. Some songs that I think are some of Therions lamer songs some people really like. Some people like a certain singer some don't. I like piotr but I just don't really like him. I don't think his voice iis amazing.