I think it could go either way lol might be draw, but Tobi have S/T so perhaps he will just have that little edge but that could carry him to victory at decisive moment.
Gedo mazo can compete with complete Susanoo
both have Sharingan and Rinnengan lol.
nothing could really hurt Tobi when he decide to go ghost mode.
no physical or ninjutsu could hurt I think.
both can try suck other person's soul though lol probably turn into soul sucking fest because that's only way really to defeat.