i don't like either band so i can't really be objective. linkin park is godawful, and stone temple toilets stole a perfectly good gas station logo and ruined it. their music was to grunge what green day was to punk, and that's not a compliment.
that being said, sounds like a match made in heaven.
what a weird contribution to this thread. STP was to grunge what Life of Agony was to grunge in that circumstance. I know you're older and wiser and whatnot, but if you're knocking down the band, play me the bass line from Big Empty.