How good are Tornadus and Thundurus?

[Six Trails]

Smogon has them both as OU, though I never see anyone online using them. Are they good? Or is Landorus the only good one in the trio?

 

[Uchiha]

Thundurus is one of the better twavers because of prankster. I don't see Tornadus being that useful. Toradus Therian is good though.