As for Lambardo being better, I dunno... I would say equal. Besides Kerry King is the biggest asshole on the face of the earth!
Then again, douchebaggery seems to be normal for old school metal artists. Dave Mustaine of Megadeth and Jeff Becerra of Possessed for example.
As for greatest drummer... Mike Portnoy and Igor Cavellera are the best to me.
That's one of the reasons I like Anthrax more than Metallica, Megadeth and Slayer (though I like them all, too). The guys in Anthrax tend to just let their fans toot their horn for them, as it should be. Anyone I've known who has met them has said that they were cool, modest, down-to-earth guys. Especially when you compare to the guys in Slayer, Megadeth and Metallica.
Anthrax aren't as famous or mainsteam as Metallica, they're not evil like Slayer and they don't have the sound technicality of Megadeth but they still kick ass with what they do, so the fact that they're not known to be pricks makes them even better. They have so much more appreciation for what they have while the others think the world owes them. Maybe it has something to do with being from New York, while the other 3 are from California. You couldn't be a west coast band in the 80's if you didn't have the Jim Morrison/god's gift mindset.