I have to disagree.
Lars can keep near perfect time and he pretty much nails everything he plays.
Though what I can say is that his drum beats and stuff are really simplistic and boring a lot of times, but that doesn't mean he sucks, just that he's not very technical. He never really uses double bass either, but he did on "...AJfA" and did great on that.
Since I never hear him play with any kind of technical prowess, I can't tell really what he can and can't do on the kit. Though I can say this, it makes him a good drummer if he can't play highly tech ****, because he doesn't try to play it. I hate when drummers (or any kind of musician) try to play beyond their skills and **** everything up, and that's a sign that they blow, because they don't have enough sense to know their own limits.
I am a guitarist, but I can play more technical **** than Lars on the drums, but Lars is still a better drummer than me because my **** is sloptastical unless I'm playing like a basic beginner beat (bum bum cack, bum bum cack...). Then again, I'm not a drummer.
But, he does look really white-trashy.
Now I did find this...
I wouldn't exactly call that not good. Sure it's not extremely amazing, but it's better than average at least. Now obviously Hetfield is no drummer, but listen to how sloppy his playing is. That's shitty drumming.
I also sometimes hear people say he's overrated, this I have to also disagree with. I never hear anyone talk about Lars or his drumming, and what few times I do, it's always somebody talking about how much it sucks, so if anything, he's kind of underrated a little.
Also, go back and listen to the album Kreator - "Coma of Souls." Nobody ever talks about the drums on that being ****, but they're not any more technical than anything Lars has ever done, so...?