Both singers of the “early” albums were great, but I liked it best when it was two lead singers on Infinity. The contrast of the two voices trading off worked very well. But if I have to choose one, it’s Gregg Rolie.
I voted Schon, but then again I like Page over Plant, Eddie Van Halen over DLR and Brian May over Freddie Mercury so the trend continues. Never seen Perry live so Arnel is my second choice.